How To When do I "heat treat"?

Nbfaraway · Jan 20, 2018

Ok, so I am very new to knife making, and Ive been watching alot of video and doing research.
I bought a piece of 10-95 HC steel online (was recommended).
Before I get to grinding and filing away, What would be the order I do it in?
Do I need to soften the metal first? (if so how do i do it? and what would the method be called?)
And I Temper the blade last correct? (will the tempering warp the blade if the blade is too thin?)
Please provide steps from start to finish just to make a simple 10-95 knife blade (no handle)

danbot · Jan 20, 2018

Simple way...
The steel should already be in a soft condition (annealed) from the get-go.
Cut out your shape and grind and file away everything that doesn't look like a knife.

Then have it heat treated or HT it yourself. A HT oven is best, but you can use a torch if you are careful. The steel is gradually heated up to its "critical" temp. This is the point where it becomes non-magnetic. Then it is cooled very quickly in quenching oil. Some people use Canola oil. It's cheap and seems to get the job done from what I've heard.
Then the knife is tempered in an oven. 500 Degrees F for an hour or so outta do it! That should give you ~59-62 HRC.
YMMV.

Hope this helps!

Nbfaraway · Jan 20, 2018

Thank you very much! knowing that it should come already annealed helps out a ton

zhyla · Jan 20, 2018

There’s a knife maker section here that was helpful when I got started. There’s a section on reddit as well that is very friendly.

You probably won’t do well with a torch and 1095. But a HT house can do it for a small price.

Make sure you don’t grind it all the way down to a point before HT. You want at least .015” thick at the edge or it will get wavy during HT.

Good luck!

I initially wanted to say you posted this in the wrong section, but honestly, every knife enthusiast should grind at least one knife. It really deepens your understanding and appreciation when you see a blade done well.

Korean Hog · Jan 20, 2018

zhyla said:
There’s a knife maker section here that was helpful when I got started. There’s a section on reddit as well that is very friendly.

You probably won’t do well with a torch and 1095. But a HT house can do it for a small price.

Make sure you don’t grind it all the way down to a point before HT. You want at least .015” thick at the edge or it will get wavy during HT.

Good luck!

I initially wanted to say you posted this in the wrong section, but honestly, every knife enthusiast should grind at least one knife. It really deepens your understanding and appreciation when you see a blade done well.

Or if you goober it up

you really appreciate just how difficult it can be to make a decent knife

, never mind the many exceptional models out there. ESEE, Becker, Busse and on and on

zhyla · Jan 20, 2018

Korean Hog said:
Or if you goober it up you really appreciate just how difficult it can be to make a decent knife, never mind the many exceptional models out there. ESEE, Becker, Busse and on and on

Just remember inside every screwed up blade is a smaller blade hiding inside

Korean Hog · Jan 20, 2018

zhyla said:
Just remember inside every screwed up blade is a smaller blade hiding inside

hahahahaaha

I've made quite a few kiridashi for that very reason

i4Marc · Jan 20, 2018

If you are new enough at this that you aren't sure how to heat treat the blade I would suggest not cutting out your blade design yet. I would strongly suggest that you draw your designs on PAPER first. Post those drawings here so that experienced and knowledgeable folks can guide you towards a practical, well proportioned and pleasing design.

1095 would not have been the steel I would have recommended but you have it so you'll have to work with that. 1095 requires a little care. With all that carbon you need a way to hold the steel at a particular temperature fairly accurately for an extended period of time. That will be tricky with a torch. The "Stickies" section will have all the information you can absorb and more. Start doing some reading. If you don't have the equipment to heat your steel reliably and don't have a proper quenchant you can send the blade to a professional heat treater for not too much money.

A very basic outline of the process is:

1. Sketch out your designs. Work out the proportions and lines/features on paper where making changes is quick and easy. This will help you determine what size piece of steel you need in the first place.
2. If your bar of steel has a curve or bend in it, straighten it.
3. When you have worked out a design, glue it or scribe it onto your bar of steel.
4. Cut out the profile of the blade/knife.
5. Scribe a centerline or lines along the edge of the blade/knife blank.
6. Drill your pin holes, lightening holes, lanyard holes and any other holes BEFORE you harden the blade.
7. Rough grind your bevels. Do not grind them all the way. For instance, if you plan on a full flat grind where the grind goes all the way up the blade, stop 1/4" or so from the top. You will be grinding more after the blade is hardened so leave yourself room to walk up to your final line. Also, leave some thickness at the edge. The thickness of a quarter should be fine. Not only will a little thickness at the edge help to minimize warpage but the surface of the blade will lose carbon during the heat treating process. The thickness you leave will be a sacrificial layer which will be removed during your post heat treat grinding.
8. Normalize and thermal cycle the blade. Read the stickies for more information.
9. Austenitize the blade, meaning heat the blade to the temperature from which you will be quenching and hold it at that temp for the appropriate amount of time. Read the stickies for more information.
10. Quench the blade, meaning cool it quickly in the appropriate medium. Read the stickies for more information (see a theme developing here?).
11. Temper the blade. After the quench the steel is highly stressed internally and very fragile. Tempering trades a little bit of hardness for a lot of toughness. It also converts retained Austenite to untempered Martensite. Say it with me....read the stickies for more information. Your temper cycles are where you will remove any warps from the quench. We'll cross that bridge if/when you come to it.
12. Back to the grinder. Grind your bevels to the final dimensions and contour lines.
13. Hand sanding. You're gonna love that part.
14. Fitting the guard, if your design calls for one.
15. Rough shaping the handle and/or excavating the tang hole.
16. Glue up.
17. Final shaping and finishing of the handle
18. Make the sheath

There are a hundred other steps. You will discover them for yourself. Don't bite off more than you can chew. When you are unsure or having trouble, check in here and ask your questions. Folks here like to help.