How to instructions for making a knife

[Stacy E. Apelt - Bladesmith]

These are the instructions I use to get someone started with a profiled stainless steel knife blank. I send it to new makers when I send them a blade blank and handle kit.

I thought there might be those who could use the tutorial and pointers. Some details are specific to a particular knife project, but the info is universal. You can start with a bar of any type of steel and shape it to the knife profile you want. 1084 is a good starter carbon steel, and CPM-154 is a good starter stainless steel.



Files needed are a 10-12" mill bastard (or a magic-cut), and a 10" second cut file. A finishing file is nice, but not necessary. Here is a great file and filing tutorial - http://www.appropedia.org/Filing_Metal

As to the paper, use wet-or-dry metal working paper in grits from 100 to as high as you wish. Most folks use it in steps of roughly doubling the grit. A good set would be, 100/220/400/800/1000/1500/2000/2500. Buy the best paper available. 3M or RhynoWet are both good. I am posting this in two parts.





Part One - Basic Instructions:

The knife:

I have preformed the knife shape to your template. The handle scales will be rough shaped and drilled to accept the Corby bolts. When you get the knife, unscrew the bolts and remove the handles. Take a look at how things fit for reassembly later.



Let's get the names of all the parts clear.

The end of the handle is called the BUTT.

The two pieces of wood are called the SCALES.

The attachments for the scales are called RIVETS. The type of rivets I am supplying are called CORBY BOLTS.

The flat area directly in front of the handle is called the RICASSO, and is the space between the end of the bevels/cutting edge and the handle.

Any inward curve or indentation at the ricasso area or ricasso end of the handle is called a CHOIL.

The little rounded notch at the end of the sharpened edge (at the ricasso) is called a SPANISH NOTCH

The top of the blade is the SPINE.

The cutting part is the EDGE.

The taper from spine to edge is the BEVEL.

The end of the cutting edge and bevels is the PLUNGE LINE.

The handle area above the ricasso is the TANG. There are several types of tangs.

The taper from the ricasso to the tip (looking down on the spine) is called DISTAL TAPER.

The point is the TIP.


Work area and procedures:

Find a place where you can safely work on the knife and have room to move. A picnic table outside will work, or any small work surface in the garage. Don't use the kitchen table or the resident cook may become upset with you.

If possible, screw or clamp a strong piece of wood so about 10 inches sticks out from the corner of the worktable. This is the sanding arm. A piece of 2X4 will work. The knife is clamped/screwed to the board, with the edge just off the wood, to allow sanding and filing. IF you curt the board to match the shape of the blade edge it makes filing much easier.

File with smooth strokes in one direction only. Never file in a back-and-forth motion.
When sanding, cut the paper into strips, and use a two-inch-wide by six-inch-long block of hardwood as a backing block. I cut 8X2" strips and use a heavy rubber band to hold the ends on the block. Get a small plastic tub or something that will hold about a quart of water for when you do the wet sanding. You will dip the block and paper in the water. Sand in one direction strokes. Most sanding should start at the ricasso and progress toward the tip. The initial sanding can be perpendicular to the blade (spine to edge) but the finer sanding should always be parallel to the blade ( ricasso to tip). When changing grits in the coarse to fine range (50 to 400 grit) change the angle of each grit so you can tell the old sanding lines from the new ones. Don't move to a finer grit until all the scratch lines from the last one are gone. It is very hard to get them out later. They have a nasty habit of showing up again as you get to the fine grits. If you see a deeper scratch.....stop....and go back at least one grit until the scratch is gone .... then proceed back up the sanding steps. Skipping grit sizes is not going to speed things up. Progress from the coarse grit to 400-800 for the pre-HT sanding. In final finish, the finer the grit, the better the blade looks. The rule of thumb is to double the grit size (more or less) each grit change. That would roughly be 100,200,400,800,1000,1500,2000,4000,8000. When doing the final sanding some people sand dry to 800, then wet sand to 8000. I generally wet sand all the time. With the 3M polishing papers (the multi-colored pack) wet sanding is not as necessary but works very well if you go that route. Wet sanding will give you a brighter and shinier final finish. Save the 3M papers for final finishing after the HT. They are super for getting the handle sanded and polished. When wet sanding, clean off the blade, the block, and change the water in the tub at each grit change. The sanding water should be - a quart of water, ½ teaspoon dish soap, 1/2 teaspoon of baking/washing soda. More on sanding later.

Getting Started:

Mark the blade tang with a marker where the handle ends at the ricasso. When working on a blade, don't sand or file any of the metal that will be under the handle scales, or the wood may not sit flush with the tang when reassembled. This is a common error, and often shows as a little space where the handle comes down to the ricasso. Avoiding it now is how to keep from having to deal with it when you start to assemble the knife and discover that the ricasso is curved up under the handle a bit. By marking the handle area, and not doing any sanding/filing there, you will assure that the area is still flat when you finish the knife after heat treatment. Some folks tape this area with masking tape (the blue painter's tape is what I use), to make it clear that there is to be no work done there. That is a good procedure to learn. I often tape any part of a knife that I am not currently working on - the handle area when doing the bevels or the blade when working on the handle, etc.

Decide how you want the blade to be beveled, and where the plunge line should be. For this blade, I suggest a full bevel - from edge to spine - and the plunge line about 3/8" to 1/2" in front of the handle. A good trick to keep the plunge even and straight is to clamp a piece of steel on the blade at the plunge to guide the file and act as a stop. Here are special made File Guides made from carbide for this task. It is a good investment when accumulating equipment.

Screw or clamp the blade to the board. Clamp the plunge guide on the blade at the ricasso. File the bevels in slowly. Take a little off at a time, easing up on the final shape. Flip the blade and work the other side regularly, allowing the shape to form from both sides. Don't try to do one side and then the other. That takes a lot of experience, and gives many old smiths trouble.

Stop each step before it is fully to the point you want. Look it over carefully before taking the final strokes of the file. It is easy to take a little more metal off later, or to go back and change the shape, but impossible to put any metal back on once it is filed away. Also, don't file the bevels to a sharp edge. This is one of the most common errors. Leave the edge a fairly wide flat surface. About the thickness of a dime in the filing stage (.040-.050"), and half the thickness of a dime after sanding before HT (.020-.030"). Always remember that the next step will take off some more metal. I suggest filing to 80% shape, sanding to 95% shape, HT, then final sanding to shape. The last step after the handle is assembled is forming the edge secondary bevel and final sharpening.

 

[Stacy E. Apelt - Bladesmith]

OK, here is part two ( in two installments). It is part of the book I am writing.
Post HT finishing

Once you receive your blade back from the heat treater it may look dark, spotty, and unattractive. It was shiny and smooth when you sent it off, they must have ruined it! Don’t despair. The changes are normal.

The first step is to remove the layer of discolored and de-carb metal on the surface. Start with 220 grit. paper. Clamp the blade on the work board , and using the sanding block,
OK, get filing:

When the bevel looks good, and you are happy with the plunge lines, it is time to start sanding. Sanding is where the blade shape takes on the final look. It goes fast in the coarse stages, and slower in the fine ones. Use even firm pressure on the sanding block. Avoid using a piece of folded up sandpaper and your fingers. You can easily make dips and waves in the blade that will show up after the final grits like a fun house mirror. Grits below 400 should be done on a backing block and applied just like they were a file. Finer grits don't gouge the metal as much and can be worked without a block if needed, but the block is your friend if you want straight and flat bevels. The block can be hardwood, aluminum, or steel. A final sanding block for very fine paper ca have a surface padded with hard leather.

Once the filing is done, you can remove the tape from the tang area, but be careful that any sanding done at the ricasso still leaves the tang flat. The tang does not need to be sanded smooth, and bonds better with a rougher surface. Initially, a few strokes of the file to assure it is flat is all that is needed. The best way to avoid the ricasso dips is to flat sand the tang and ricasso area together with the sandpaper laying down on a smooth and flat surface and moving the knife over it in smooth strokes. A granite surface plate is a very useful tool, but a piece of granite countertop or a sheet of thick glass will do to start. Sand the tang/ricasso to 200 grit, then gently sand the ricasso area to 400. Now, you can proceed to the blade bevels without much risk of rounding the ricasso up under the handle. When the blade bevels are sanded to 400-800 and all surfaces are scratch free, the blade is ready for HT. If working from your own blade blank, be sure to drill all holes in the tang before the HT. You will really hate yourself if you don't. Also, the holes should be about .050-.060" larger than the rivets/bolts used, so for an 1/8" pin, drill a 3/16" hole; 3/16" -drill 1/4"; etc. Too large isn't a problem....too small can be a big problem later on after the blade is hardened.



Heat Treatment:

When the blade is sanded to 400 and all is well, it is time for the heat treatment. This is where the soft (relatively) pearlitic steel is going to be changed into hard martensite. The blank provided is ATS-34. The blade needs more than just getting it hot and quickly cooling it off if you want a superior blade. It will be heated to 1900F and held there for 30 minutes, then plate quenched to cool and remain straight. After that it will receive two temper cycles at 400F.

When it is ready for HT I will do it, or you can have someone else do it. You won't be able to do it yourself for stainless steel, and carbon steel still requires some degree of heat control.



Take your time. Spending a few more hours/days/weeks on the blade will result in a far better finished product than trying to rush it out in a single day/weekend.

Work a while, take a break, and when you come back, examine the progress before you start back up. You may see some area that needs attention that you would have gone right past.



Part Two - Finishing your knife:

Once you receive your blade back from the heat treater it may look dark, spotty, and unattractive. It was shiny and smooth when you sent it off, they must have ruined it! Don't despair. The changes are normal. It is caused by the surface getting hot in HT. It will be sanded off in finishing the blade.

The first step is to remove the layer of discolored and de-carb metal on the surface.

Put a quart of water, a 1/2tsp of dish soap, and a 1/2tsp of baking/washing soda in the plastic tub. Dip the sanding block in this and sand, re-wetting regularly. Wipe off the blade often, too. Other ways of wet sanding include using a spray bottle of water/soap or using Windex.

Start with 220 grit paper. Clamp the blade on the work board, and using the sanding block, wet sand the blade completely ... exactly as you did before. Once the surfaces are cleaned and bright, start going up the grits. At 400 grit switch to making all strokes longwise, and use an even but firm pressure. Try to avoid any strokes that don't follow the blade length. When the 400 grit is done, the blade should have a bevel that comes to almost an edge. Don't let it get sharp yet. You really don't want to be sanding on a blade with a sharp place on it. If the edge gets sharp, dull it with a few strokes of 220 grit paper along the edge. Look the blade over really well. If the surfaces are smooth and defect free, continue. If they are not, keep on working the 400 grit. You can quit sanding here for a field use blade or take it up to a much smoother and shinier finish When you think you are ready to move to the next grit, wash the blade, change the water, wash your hands, and clean up any water and sludge from the previous coarser grit. These things have a bad habit of coming back to make scratches later. Examine the clean dry blade in a strong side light (using an Optivisor or other magnifier is a good idea). Look for any scratches from the last grit that are still showing. If there are scratched, dips and ripples, blurry places, etc. go back to the grit you were doing and work some more. If the scratches are bad, go back one grit coarser. The point is, don't move on until the current grit is completely done.

When done for the day wipe down the blade well and completely dry it when done for the day. A light coat of oil is always a good idea when setting a project blade away for the day.


At 2000/2500 grit, the blade should be smooth, shiny and scratch and ripple free. If it isn't, that means you did not completely finish a previous step before going on. The temptation is to say, "Heck, it is my knife, that is good enough." ... Don't do it! You owe it to yourself to do a good job. Go back and take the time to re-sand as needed. I have often found a small place I missed and gone back to 220 grit and completely re-done ten or twenty hours of work. It is worth it in self-pride alone.

 

[Stacy E. Apelt - Bladesmith]

Now, open the package of 3M polishing papers. Notice that each has an abrasive side and a "cloth" side. Each is a different color to designate its grit equivalency. The package has the grit size and colors on it. Take a sharpie marker and put an X on the back of each sheet so you can tell the abrasive side from the back. The white paper is very hard to see the difference so marking it while fresh is important. You can also mark the grit number as well. These papers can be used until they are shredded, so keep them after use for other sanding projects, especially handle work. Also, keep them in a plastic bag when not in use. You don't want them contaminated with sandpaper grit and making scratches. I go back to the green sheet - which is about 400 grit. Since you have gone way past this point already, progress up the grits will be fast, but you will notice that then surface gets smoother and shinier than it did with the sandpaper. The papers can be used wet or dry. Try it both ways, but I usually go dry, as they polish so well. You should use the sanding block up until the blue sheet, and then can switch to folding the paper, or continue to use the block. I have a 2X1X4" hard felt block that I back the papers with. Going all the way to the white sheet is a polish up to about 8000 grit. The blade should be mirror shiny at that point. If you want a more matte finish, just stop at a lower grit, or go back down the grits until you get the desired look.



OK, now your blade is polished. Keep it that way by wrapping tape to protect the smooth shiny bevels. The blue painter's tape is the best. Another trick is to wrap the blade with a layer of paper toweling, and then tape over that with the tape. This is easier to remove and requires less clean-up of the tape's adhesive. In any case, the blade should be well protected from sanding grit, tools and other hazards during the handle work.

Take your handle scales and look them over. Are they a good match? Is there a certain orientation that looks best (grain direction, burl pattern, etc.)? Are they the right material for the knife? Again, just as in the sanding, don't accept OK as good enough. If they look right, fine. If not, change them or modify them to be right.

Mark the inside of each scale and put an arrow towards the front and top. This sounds silly, but you would not believe how often one is put on or drilled backwards. Place the scales together, and tape them tightly.

The front end, where the ricasso will be, needs to be shaped and sanded before assembly. Saw/file it to any curve needed, sand it smooth, rounding up to the flat sides. Sand the ends to 800 grit or finer. They should be smooth and scratch free. This area will be impossible to sand and polish without ruining the blade finish once the handle is on the knife, so make sure it is right. If you are applying a finish to the scales, apply it to the ends and sand/buff/polish it now . The scales only need their front ends done right now, the rest can be a rectangle, you don't want to shape anything else yet.

I hope you remembered to drill the holes in the tang before HT, because that will be a lot harder to do now. Also, the reason you want to drill the holes a bit large is to allow for any miss alignment in drilling. I make the holes at least 1/16" larger than the rivet.

Lay the blade over the still taped together scales and position it where the scales should be. Use a clamp to hold it there and take a look at arm's length to check the positioning. Once it looks good, mark the exact center of each rivet/bolt/thong hole. Set the blade aside for the moment.
NOTE - It is best to determine the correct drill sizes on a piece of scrap wood before drilling the handle.
While the scales are still taped together, drill the front hole through both scales, using a drill press if available. Drill as straight and accurately as possible. Use a drill bit that is a little smaller than the pin/rivet that will go through that hole. Re-drill it with the correct size bit. The correct size is a few thousandths over the pin size, so a 1/8" pin gets a .130" hole, or there about. You should measure your pin stock to make sure of its size, as they vary in actual diameter. Now, take a piece of the rivet stock you will be using and check the fit. Sand the ends of each rivet to a slight chamfer to aid with insertion. Re-drill as necessary until the rivet goes through with little or no pressure needed. Leave the rivet in place. If using Corby bolts, drill both sides for the shoulder, and screw in a bolt. This step you just complete now has the two scales firmly locked together to make sure the rest of the holes will all align. Now it is time to drill the back rivet. Drill it the same way, inserting a rivet in the hole when ready. Continue to drill any other holes as needed, fitting the rivet/tube/etc. as you go. If you cut the rivets ¼" longer than the scales thickness the rivets will be ready to install during assembly. When all is done, remove the rivets/bolts/tubes and take the tape off the scales. Place on the blade and dry fit, going in the same order as before (front, rear, etc.). If there is any trouble going through the blade tang, re-drill that tang hole to make it allow the rivet to pass through. A carbide or diamond burr in a Dremel tool will enlarge it quickly. Once all is fitted with the blade in place, remove the pins again. Lay the tang on the inside of one scale, aligning the holes carefully, and gently clamp it in place. Trace around the tang with a pencil (avoid markers, as they can absorb into the wood and make stains that show later). Do the same for the other scale. Cut the excess off with a coping saw, or a band saw if available. You don't want to get any closer to the tang than 1/8". The rest will be filed/sanded away. If desired, do any pre-shaping needed. Check all fits again and if it is good, you are ready to assemble the handle. Tape the blade ricasso to keep the epoxy from running down the blade, leaving about ¼" of the ricasso exposed

 

[Bufford]

Very well done, this should be a sticky. A beginner with a bit of practical experience with tools should have no problems making a knife with this advice.

 

[Stacy E. Apelt - Bladesmith]

Gluing the handle on and finishing the knife:

This is a good time to talk about adhesives. The best way to assemble a handle is to glue and bolt it together. That way it is never coming loose. This is not always the way it is done, so the glue should be able to do the job by itself. With the exception of Corby and Loveless bolts, rivets are mainly just to prevent lateral blows from shearing the glue joint. Top grade structural epoxy is what you want for the job. Forget all the advertisement hype about super glues and Gorilla glues, etc. They all have things they do best, but for handles, epoxy is king. There are many types available, but the slowest curing time and maximum strength make for the best joint. Don't use 5-minute epoxy ever. Acraglass is a resin made for gun work, and is really good, but the 24-hour cure epoxies from any woodworking shop will be just as good, and much cheaper. I prefer System Three T-88. Get your epoxy resin from a place that moves a lot of glue to assure fresh resin. Mix the resin in a small disposable plastic cup (I use the 2oz. condiment cups). The ratio of hardener to resin is critical, so get it perfect. Using a scale is a good way to assure things are equal. (Note that the part A is usually a tad heavier than part B per volume. Look at the bottle for weight instructions.)

Spread newspaper covering the entire work area, put on work clothes, and put on a pair of nitrile gloves. Lay out about five or six pieces of paper toweling (I tear them into ¼ sheets) and unscrew the lid on the alcohol can. Check that everything is ready, and all materials and tools are there. Hit the bathroom, kiss the wife, do anything that needs doing for the next hour. Once you mix the epoxy the clock is ticking. You don't want to get epoxy all over your gloved hands and suddenly realize you don't have something you need.

Stir the two parts of the epoxy well with a popsicle stick for one minute. I mean a whole minute! The epoxy can be cleaned up easily with denatured alcohol while uncured. Acetone will remove cured epoxy with some elbow grease, but the solution is to clean up any excess and drips while it is uncured or half cured.

Take the pins and tubes and lightly roughen them by rolling them across a sheet of 120 grit paper. Don't sand them up and down or they will get smaller. Corby bolts need no preparation.

Apply the resin to the rivet holes on the scales first, getting it down in them with a bamboo skewer or toothpick if needed. Now put some resin on the rivets and slip them through one scale. If using Corby bolts, don't get resin in the female bolt hole. Apply epoxy to the inside of the scale, place the tang over the scale, apply resin to the exposed tang, and place the other scale on. Snug this sandwich up with your fingers until the rivets are evenly sticking out both sides, and the scales are positioned on the blade in the correct alignment. If all is good, clamp it or tighten the Corby bolts snug. Don't tighten or clamp too hard.



Now, let's talk clamps and gluing. The purpose of a clamp is to hold something in place. In this case while the glue cures for a day. If you clamp the scales to the tang so hard the glue all gets squeezed out, you have defeated the entire purpose of all the work you just did. All you need is a couple of light tension spring clamps ($1-3 at the hardware store). If you can't easily open it with one hand, it is too powerful. All it needs to do is hold the scales down against the blade with a layer of glue between the two. There are several ways of preventing a glue starved joint, and thus not having to worry about the clamp strength. The simplest is to drill a lot of 1/8 " to 1/4" holes all over the tang ... called "Swiss cheesing". This allows the epoxy to pool between the scales, effectively making epoxy rivets, and assuring a strong joint. When using structural epoxies, like T-88, this is an excellent choice. The other way is to grind out (hollow grind) the tang center, leaving only about 1/8" of surface around the perimeter of the scale area. This makes a shallow reservoir of resin between the scale and the tang, which can't be squeezed out by the clamp. One of these procedures should be used on any glued-up handle.

Back to the clamps. Two clamps are far better than one. They don't need to be as strong, and you can position them to make sure the scales are in contact with the tang evenly. Place one in the front at the ricasso to get a seamless seal, and one in the back to make sure the butt does not rise up. One strong clamp in the center can actually make the ends curl up, causing a gap at the ricasso and butt.

Take a piece of paper towel and wipe any large amount of excess epoxy off the handle sides (no need to do much more than avoid dripping). Take another clean piece and wipe the excess at the ricasso, making sure you get any off the finished ends of the scales. Put some alcohol on a new piece and wipe the ricasso area again. Don't overdo it with the alcohol at this point, you only want to remove any epoxy puddles. Too much solvent, and you can affect the epoxy strength. Set the clamped knife down flat (not edgewise) and let it sit until the epoxy in the mixing cup is starting to set up. This can be from 10 minutes to 6 hours, but for T-88, and most other 24-hour resins, about one hour is normal. While you are waiting for the epoxy to gel, clean off all tools and things that have epoxy on them. and put them away. Use alcohol or acetone as needed. Wash your hands well with soap and water to avoid any contact dermatitis caused by the chemicals in the epoxy and the solvents. Throw away any paper towels you used and tidy up the work area. There should be nothing but the clamped knife, the alcohol can, the epoxy in the mixing cup, and some paper towels left out.
Note - A good hand lotion like Cera-V is a wise way to keep your skin from damage in knifemaking.

Check the clamps and handle after 10 minutes to make sure nothing has moved, then set it back down. Another quick wipe at the ricasso with an alcohol dampened paper towel may be necessary if there has been more squeeze out.

Once the epoxy is gelled in the mixing cup (about an hour), clean the ricasso area again with an alcohol dampened (not soaked) paper towel. Clean any resin off the untaped areas of the blade. (Now you know why we taped up the blade so well).

Set the knife down and go do something else for the rest of day. Leave it undisturbed for at least 12 hours … OK, we know that’s not going to happen, but let it sit for four to six hours before picking it up to check, “One last time”. Remove the clamps, clean up any spots that need it with acetone. And set it aside to cure until tomorrow. If you follow this procedure, you will have a very strong handle.

Once the epoxy is cured, tape up the ricasso right up to the scales. Put several layers of tape here, as it will get abraded when sanding the handle, and you don't want to mess up the nice sanding job you did earlier.

Clip/saw/file off any excess rivet material and file it flush with the scales before starting to shape the handle.
Go slow, removing a little here and a little there. The first step is to take the scales down to the point where the tang metal shows all around the sides. Then, round the corners and edges to make the handle a roughly oval or egg-shaped cross section. All this can be done with files, rasps, and coarse sandpaper. Look it over and make any adjustments in the profile as needed. While a belt sander makes this an easier job, it can be done by hand. Most inexpensive 1" belt sanders (Harbor Freight, etc.) do a fairly good job on handle work. A Dremel tool can be used, too.

After the rough shape is done, continue to refine it and smooth it, starting with 120 then 220 paper and going up the grits to at least 800-1000 grit. At some point you will have to un-tape the blade and make sure the handle and spine are a smooth transition. Just be careful not to scratch the blade. While fairing in the spine, tape the sides of the blade to protect them.

The 3M polishing papers are the absolute champ at handle finishing and can make your handle shine like glass with no finish at all if the material is suitable (many stabilized woods and some exotics are great for this). I recommend a set of the papers that are kept to only sand handles. This will prevent them darkening light color woods from the metal swarf from previous use on blades.
If you are using a finish on the handle, apply it in very light coats, and rub it into the wood (not painted on the wood), and wipe off the excess after a few minutes. Allow to dry and sand off until the surface is just down to the wood. Repeat until it will take no more into the wood. Allow to dry for several days, then finish out with the 3M papers for a prize-winning shine.

Un-tape the blade, and clean everything well. Check for any small rubs and scratches and fix them now with the 3M papers (hopefully there will be few or none). The tendency for scratches and blemishes to show up at this stage ... and the words that it makes you say ... are why very few ministers make knives. Buff up everything with the last two grits of 3M papers and your knife is done.

 

[Stacy E. Apelt - Bladesmith]

Make or purchase a sheath if it to be carried, but never store the knife in the sheath. Storing in a sheath is a sure way to find rust spots later on. Always oil a knife when putting away for any period of time. A zippered pouch is the best place to store a knife.

Sharpen the knife carefully. First create the secondary bevel by slowly working the edge on a medium stone. DMT diamond stones are excellent. It is wise to tape up the sides of the blade to prevent accidental scratches in sharpening. Once the secondary bevel is formed to a sharp edge, refine it on a fine and extra fine stone. Polishing the edge on a leather strop charged with rouge is the final step. This removes the "wire" formed in sharpening. Cut a few pieces of printer paper to check for rough or dull spots.

Congratulations, you have made a knife that you will be proud of. You can someday pass it on to a child or grandchild.
On that note, never sell or give away your first knife. It may be tempting, but don't do it. Someday you will regret it.
Ever wonder where the first knives made by Moran, Loveless, Scagel, Randall, etc. are??? and what they are worth? You never know, your first knife may be one of those someday.



Please feel free to ask questions while working on the blade. If you can take photos of the progress, do so by all means. They will help me or other see what you are doing and will be useful to you when you post the "My new knife" thread.

 

[kdiver58]

I have a small sand blaster I have filled with glass beads .. instead of 200 paper after heat treat what do you think of bead blasting it ?

Thanks for a top notch tutorial .

 

[Stacy E. Apelt - Bladesmith]

If one is available, many makers prefer to bead blast for a nice matt finish.

 

[Stacy E. Apelt - Bladesmith]

I have been asked to sticky this article I wrote....so here it is:

It seems clear that many people don't understand what is happening in the steel when it is hardened and tempered. I will try and give a short ( OK, not so short) explanation, but one of the problems ( like yours) from folks who learn on the internet is that reading three sentences and spending three hours trying to learn a skill is not the same as reading three books and spending three years developing the skill. Even that does not compare to reading twenty books, attending twenty seminars, and spending twenty years practicing the skill. I often get a chuckle from the "experts" who are on their third blade.

OK, enough ranting:

Steel is a combination of iron...usually about 99%, and carbon...usually about .6-1.0%.
To that they add small amounts of alloy ingredients. Some are to make it easier to make the steel, such as silicon,phosphorous, sulfur. Others are there to enhance the properties desired in the steel -Manganese, Chromium, Vanadium, Tungsten,and some others.
The alloy ingredients form various structures that are often in the form of carbides, which can make the steel harder and tougher. This comes at a price, though, over a simple steel alloy (with just iron, carbon, and a tad of manganese). Once you start adding things like chromium and vanadium, you need more heat and longer times for these to go into solution.
When the alloy becomes overstuffed with these ingredients, as in martensitic stainless steels, the iron content is reduced to as low as 70% and things like chromium, vanadium, and tungsten go up to as much as 20%. Carbon often reaches nearly the proportions of cast iron ( 2-3%). The excess carbon is needed because of the amount of carbides formed.

What does all this mean to knife makers??????
We want our blades to have a combination of two things - Hardness and Toughness.
This comes from creating a structure in the steel called Martensite. We can then manipulate the martensite into a desired blend of hardness and toughness.

So lets get out steel hot:
When we heat the steel up to a point where the atoms start to rearrange, the first major change comes around 1350F. That point is the Critical point - Ac1 or As,which means it is the beginning of the point where the steel converts to Austenite. Austenite forms at slightly different points depending on the alloy ingredients.The word "critical" means that there is a change in the physical properties (solid,liquid,gas, structure,etc.) at that point.
Next we reach the Curie point at exactly 1414F for steel. This point is the same for all steels. Its abbreviation is Tc. This is not a physical change, but deals with ferro-magnetics. At this point the steel becomes non-magnetic. Of all the "tricks of the trade" that smiths will tell you, this is the only one that is entirely accurate and repeatable. When the blade stops sticking to a magnet...it is at 1414F.
Then we reach the point where the alloy ingredients are able to go into solution. This is the target point. This point is often called Ac3 or Af. NOTE - Charts with the "s" and "f" used are easier to read, I consider that the letters mean "start' and "finish". For this reason, I will use those terms. The target is the place where all that we want to happen will, and things we don't want won't. Grain growth is the enemy when the steel gets too much above the target point.

Engineers have spent many years doing tests on steel to determine what it does and when it does it. Each steel type has its own set of data. This data is put into charts by engineers, because they do that sort of stuff for fun.
A look at one of these funny charts with funny names like TTT or ITC will show a bunch of curved lines. The curve sort of looks like a nose, and the left-most spot is called "The Nose". That "Nose" is usually about 1000F on the chart. This is the point where if your steel goes any amount right of the nose in its cooling ( takes too long to cool down), it will become partly or all pearlite ( which is not what we want). To determine what you want the chart to tell you, look at the base of the chart and the vertical side of the chart. Along the base you will see the time expressed in seconds, and then in minutes. On the vertical side you see the temperature scale.. Thus the chart shows how soon things happen at any specific temperature . The X/Y coordinates of any spot on the curved nose line will tell you how much time you have to get down to that temperature during quench.
All those funny letters and names assigned to the places along the temperature chart tell you where the steel changes from one structure to another. A= austenite; M= martensite; Ferrite is iron and carbon ( body-centric for those engineer types); Cementite is a hard and brittle structure of iron and carbon; Pearlite is a soft structure made up of layers of ferrite and cementite.
Lower case sub letters, "s and f" mean start and finish. Letters "c and r" mean climbing and returning...or simply heating up and cooling down. Note that things don't always happen at the same point rising and falling.

What we are concerned with is taking a piece of steel that we have shaped into a blade and changing it from one structure to another in a controlled process we call "Heat Treatment".
We do this by first heating the steel up in an environment that won't ruin the blade. This is part the atmosphere of the forge, and part how we protect the blade form elements we don't want to add to our steel....mainly oxygen. That is for another discussion, though, and for this talk we will assume your forge/oven atmosphere is right and you did the proper things to protect the blade form evil oxygen.

Back to the funny chart. The steel starts off a mix of God-knows-what structures after we have been working on it. In the final Heat Treatment we heat it up and as it passes As/Ac1 it starts to change into austenite. Then it passes the Curie point, and our trusty magnet ceases to attract the blade. On we go as we heat up the blade until we reach the Af/Ac1 spot. This is where we want to stop heating the blade and hold it at that point ( as close to evenly as possible) during what is called the "soak". While the blade is "soaking" the alloy ingredients have time to slowly recombine into various structures, go into solution, and the evenly distribute themselves. This takes from 5 to 10 minutes for simple steels, and up to an hour for complex stainless steels. As a general rule of thumb, a 10 minute soak is used for carbon steel alloys, and 30-45 minutes used for stainless steels.
The temperature of this varies depending on the alloy ingredients. Simple carbon alloys are usually about 1400F to 1500F, and stainless steels are around 1850F to 2050F.

Once we have allowed the ingredients to go into their solutions and such, we now need to cool the blade down and make Martensite out of it. This is the "Quench" stage. By rapidly dropping the temperature past the "Pearlite Nose" we can super-cool the austenite and thus not make any pearlite. Notice that once past that nose, the amount of time starts to expand as the blade cools down. This is why we need different quenchants and methods for different steels. All we want to do is get past the nose quickly, after that we want to cool down at a rate that allows the steel to convert to martensite , but does not shock the steel any more than necessary. For some steels, like the simple 10XX series, this is fast,one second to pass the nose, but as we add those alloy ingredients, the amount of time to pass the nose increases. The "O" series steels have about ten seconds, stainless steels give you many minutes to pass the nose. Thus, the proper quenchant for these steels would be -
Water or fast oil for 10XX steels
Slower oil for O series and alloy steels like 5160
Air for D-2 and stainless steels.

Once past the nose, we can slow down the cooling rate. The steel needs time to prepare for the sudden change that will occur at the point where it changes to martensite. At this point we still have austenite ( hopefully) and the steel is rubbery soft and in no danger of cracking or breaking. As we reach the Ms point, around 450-500F, the steel rapidly converts into martensite. This is where the cracks come from. The change in structure can tear the blade in half. Thus we need to cool the blade across this area as slowly and evenly as possible. The choice of quenchant can make or break ( literally) a blade here. At about 200F the austenite has mainly converted to martensite. Any left over austenite is called RA, or "retained austenite". This is a very small amount in simple steels, and is dealt with in the tempering stages. However, with the complex stainless steel alloys, this RA is a big problem unless converted as fully as possible to martensite. The much larger percentage of RA at room temperature is due to the fact that ,while the simple steels finished their conversion to martensite (Mf) at about 200F, the stainless steels need to drop to about minus 200F, yes 200F below zero, to complete the transformation. This is done by adding a step called "cryo". The steel can be very unstable with part of it being very brittle martensite and part very rubbery austenite, so it is wise to give it a short stabilizing step called a "Snap Temper". This is a short temper cycle of about one hour at a low temperature of about 200F. This will stabilize the martensite somewhat and can avoid cracks forming in the cryo stage. After this "snap temper" the blade is cooled to room temperature and them placed in a chamber that will cool it to the sub-zero point where the Mf will finally be reached. This is typically done in liquid nitrogen, which is a bit below -300F, or in a solution of acetone/alcohol/kerosene and dry ice, which will cool the blade to about -100F. This is low enough to get most of the austenite converted, but the LN is certainly better. Economics and frequency of use usually decide which type of cyro one uses.
After the austenite is converted, it is a very strained and brittle structure. This is called Un-tempered martensite. This is corrected by tempering the steel at points between 350F and 1050F. The tempering target point is determined by a tempering chart which those engineers have also made up for you. The chart is much easier to read. It shows the estimated hardness at any given temperature on the curve. The first temper cycle ( after the snap temper) is to convert the martensite to tempered martensite, which is tougher, as well as convert any remaining stray bits of austenite into martensite. This newly converted martensite will, however, be un-tempered, so you need to do a second temper after cooling to room temperature. A second cryo treatment between the tempers will accomplish very little, and this is not usually done. To make it clear....cryo is done as a continuation of the cooling process during quench. After that cooling has been stopped and tempered, any cryo will be much less effective.

To state it in a flow chart for stainless steels:
Heat to austenitization > Soak > Quench > Snap temper > Cryo > First temper > Cool to room temp > Second temper

 

[Atlas Knife Company]

Thank you, Stacy. It's such a great explanation. I have one question though. If Ac1 is roughly 1350° and Curie is 1414°, then is it possible to HT and anneal without becoming non-magnetic?

 

[Stacy E. Apelt - Bladesmith]

Sub critical annealing is done around 1250F.

Some degree of hardening can happen above Ac1, and below Tc......but full solution is needed to get a proper HT. About 100F above Ac1 is the norm.

 

[Rick Marchand]

Thank you for putting the time into this, Stacy....

You mention grain growth being the enemy but only at it happening when "... the steel gets too much above the target point."... can you expand on what kind of "too much" we are talking... 100F, 50F, 25F? There are also alloys that can control grain growth like vanadium (Aldo's 1084FG is a good example)... should steels like these be sought after by open forge heat treaters?

 

[SteelSlaver]

This is one of the simplest, correct explanations of what happens and needs to happen to make knife type steels harden correctly.

Almost every base is covered, but, as in the part about keeping the oxygen from doing harm, a small mention that the steel should be properly normalized before HT begins might be added.

 

[Salem Straub]

You mean that's it?

 

[Stacy E. Apelt - Bladesmith]

ib2v4u

The original article was about stainless steel (RLW) HT and cryo. Stainless steels do not get a normalization, beyond the pre-soak at 1200-1250F, during ramp.

Also, the article was about the metallurgy concerning what happens in the steel during HT, not a how-to on HT. There have been books written on that and they still don't cover everything.

On carbon steels, the usual HT process would be followed. Normalization/stress relief is part of that process.

 

[SteelSlaver]

Right just wanted to mention it because the it covers all the other bases.

 

[Nonprophet]

Well this is my first post as I'm new to this forum, you guys come highly recommended from the Spyderco forumites! Stacey I think it's just plain good luck I checked this as I am receiving my first knife blank this week to start the sanding/finishing process and wasn't sure how to begin! Lucky me huh? I want you to know that as one of those newbies you effort to promote the interest without wanting something in return is great! It seems to be a trait singularly unique to blade makers. I have found in my quest to learn all of this stuff that people on the other end of the journey I have started are almost always willing to help and foster the desire they themselves had when they started. I don't think most professional tradesmen/women are so forthcoming! Most see it as giving away trade secrets or losing business or some such nonsense. I'm glad there are people in the world who still are interested in helping people without it really gaining them anything and for that I thank you!

 

[mostho]

An Absolute to read.
Thanks Stacy

 

[KROWINVA]

Very nice information for the novice knife maker such as me. You have saved me countless hours of practice and "hit & miss" sessions with sharing your wealth of knowledge with us. Thank you very much& best wishes to you & yours.

 

[Stacy E. Apelt - Bladesmith]

Here is a short sheath tutorial:

The making of sheaths is not all that hard. A few basic tools and some planning will usually assure a good job. There are many good sheath tutorials and videos available.

To keep the knife from cutting through the sheath and cutting you ( can ruin a fishing/hunting trip) there are a few ways to make a robust sheath

All Leather Sheath:
A leather sheath should be made from firm leather and have a welt that is glued to the outer case. Use vegetable tanned 8-9 Oz. leather. Glue the welt up with Leatherweld. This will make a far stronger welt than contact cement. Most of the knife supply catalogs carry the leather, leatherweld, edge dressing, thread, awls, and needles.
The holes should be drilled on a drill press, or punched with an awl through the three glued up layers, and the assembly saddle stitched with waxed saddle thread. The stitching should go down the sheath, not looped around the side. Saddle stitching is done with two needles, one on each end of the waxed thread. Pull it through the second hole, leaving an equal amount of thread on each side. Go back through the first hole with each needle ( one from the top, and the other from the bottom), and proceed down the sheath to the end. At the end, go back two holes to lock the thread. The saddle stitch will make the sheath pull tight from both sides, and with the glued up welt, make a very strong wall for the edge to rest against.The sheath can be finished as you wish. The outer edge of the sheath can be sanded with 400 grit,dyed black if desired, treated with edge coat (tragacanth), and then buffed. A final coat of Atom Wax (Leather Balm) over the whole sheath is always a good idea.

Lined Sheath:
A kydex or wooden liner can be make and the sheath can be fitted to the liner. This allows the use of softer leathers like the leather you are using. This method is very good for elk or deerskin Indian style sheaths, and for exotic leathers.

To make a wooden liner, use a soft, but fairly firm wood. Do not use hard, resinous, or abrasive grained woods.As you will find it hard to get Magnolia or Japanese Honoki (Ho) wood, - Holly, or Poplar are good choices. Tupelo, Aspen, and Bass (Linden) work, too. The poplar at Home Depot is cheap and will do the job. Pick a straight grained piece.
Take a piece of 3/4" thick wood and split it slightly off center down the middle. These two scales will make the wood liner. Trace the blade on the thicker piece.
Using a small chisel and/or a Dremel tool, carve out a recess to fit the blade.Try and make it even and smooth bottomed. There is no need to make it contoured to the blade's bevels. Just an even depth from side to side works fine for a sheath liner. Check with the other scale in place, and when the blade slides in and out without binding, the inletting is done. The liner should not be a snug fit...or too loose. Now, take a paint stir ( or piece of metal the thickness of the blade) and grind it to the shape of the recess so it fits exactly in the cavity. Leave the handle end on for a grip. Now, cut around the recess with a band saw, leaving a lip of about 1/4".
Using a good grade wood glue, like Tightbond, apply a thin layer to the lip, avoiding getting it in the recess. Place the wooden blade in place, and put the top half on. Clamp firmly ( but not hard) around the perimeter, and set down for five minutes. Carefully pull out the wooden mandrel, wipe it off with a damp cloth. Repeatedly insert and remove it, wiping each time, until the stick comes out clean of any glue. Dry the mandrel well and run it in and out a few more times. Set the liner down with out the mandrel in it. Half an hour later,check again for any more glue squeeze-out with the mandrel. Let the glue dry overnight ( without the mandrel, of course). Go back to the band saw, and trim the top piece to match the recessed piece. Stick the mandrel back in the liner and sand the liner until it is shaped like you want. The mandrel is much better to have in the liner when sanding than a sharp blade, and seals the cavity from grit. The final shape should have rounded sides and be thick enough to hold up, but thin enough to make the final sheath not too large or heavy. Lacquer the outside of this liner to make it more durable, and stronger. Once again, the mandrel provides a nice handle to hold on to when lacquering and to clamp in a vise when drying. Blow out the liner with compressed air any time you remove the mandrel, and very well before putting in the blade. This is to avoid stray grit from becoming embedded and scratching the blade.
Once the liner is done and you are satisfied with the fit and all, make the leather outer case. It can be made like the one you did; Made with a fringe like Mountain Man/Indian sheaths; Or pinched and draw stitched ( similar to saddle stitching) down the center of the back as in a classic leather covered wooden sheath.
It is a good idea to make the leather covering go at least 1" beyond the liner. This is to make a secure and fitted shoulder for the knife handle to seat into. Put the mandrel in the liner when you are stitching, shaping or doing any work on the cover. It can prevent the leather from overly compressing the liner and making it too tight.
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