Finishing bevels after heat treat and temper?

stingray4540

stingray4540

Joined
Mar 26, 2007
Messages
2,798
Well I know that you should leave your edge thick to avoid warping during heat treat and temper, so my question is:

How do all of you finish the bevel after heat treat and temper?

I have done the bevel so far with a file, and was wondering if the temper will make the steel soft enough to finish the bevel with a file? Or do I have to finish it with a belt grinder? I would like to finish it up with a file then some sandpaper wrapped around a file, but I'm not sure if it will ruin my files.

Call me paranoid but I tend to be a perfectionist and like the control that a file gives me because it goes slower and I can control it and I can see were I need to make adjustments before it's too late and fix them. Anyways, I haven't purchased my belt grinder yet, I'm waiting for my next pay check, so maybe I just need to try using it and maybe I'll like it more that I think?

I have been talking with another newbee make with more experience than me and he uses the belt grinder almost exclusively and sometimes doesn't even start the bevel until after heat treat. I'm just curious to hear what everyone else does, and/or what my different options are.
 
My preference is to grind the bevels and profiles in the annealed state then finish up the grind with a sharp edge after the quench. Heat treat - sand and polish to the desired finish.
 
So you grind your bevels all the way down until they come to a point and form a sharp edge(well as sharp as a file or grinder will make it) before you heat treat? Then you just sand to get the desired finish? Do you ever have problems with warping during ht?
 
I leave it just a bit thick before HT. After I hit it quick with a 220 then go to 400, 600 and form there depends on the ifnish I want. I would never grind my bevels completely after HT unless it was super thin metal like a flexible filet knife. Once you learn to grind on your grinder you will never want to use hand files again. :D
 
I've found I can leave my edges around 1/32 of an inch thick before heat treat and it seems to be sufficient to prevent warping. Make sure you normalize before heat treat, and this will help decrease warping by somewhat evening out the stresses in the steel.

This way you can bring your bevels pretty much to a finish other than final sanding, and just add your cutting edge after heat treat and temper. However, if your doing a zero bevel grind, your going to have to do some stock removal after heat treat. It's sure going to take a while with files. But that adds character, doesn't it :D.

--nathan
 
Big Jim: I'm just afraid I won't be able to get the angle right in a belt grinder. Is there any special trick you guys use or do you just do it buy eye? what I'm doing for using files is to mark the center of the edge of the metal and use a caliper to mark 5 units from my edge and draw a line to know about were the angle should start. I don't think I could use the same meathod because I don't think I would be able to se my lines if I use a belt grinder. So what do you guys do?

P.S. I measure 5 units over because I'm going with about an 11degree single bevel angle. inverse tangent of 1/5.

silver pilate: Is normalizing like anealing? were I heat it to non magnetic and just let it air cool? Yes I believe I am doing a zero bevel( I call single bevel) because there will be only one angle that creates my edge. So I can use files after the HT and tempering?

BTW: I am working with 1080 if that makes any difference to anyone.
 
The hardened and tempered steel will be hard on your files.

This is a good place to use a diamond stone. It will shape the bevels after hardening.without wear.

You can't replace a decent 2x72 belt grinder.

Good luck, Fred
 
Stingray,

Normalizing is where you bring the steel up to about 100 degrees above critical temp and let it cool slowly. You may want to soak a little bit longer than you are to make sure the heat is fairly uniform and above austentizing temperature, and then let the piece air cool in a fairly warm area like near the forge.

It sounds like you are doing a bit more of an annealing on your steel which is good when you begin to work on it, but you want to make sure you cool it very slowly for annealing by wrapping it in some insulating substance after heating and set it aside for a long, slow cool.

--nathan
 
I grind my knives after I heat treat and temper the steel. This way I do not have to worry about all of that. It works for me. I also do all my filework when the knife is done. The edge is the last thing I do. ------------:thumbup: :D
 
stingray4540 said:
Big Jim: I'm just afraid I won't be able to get the angle right in a belt grinder. Is there any special trick you guys use or do you just do it buy eye? what I'm doing for using files is to mark the center of the edge of the metal and use a caliper to mark 5 units from my edge and draw a line to know about were the angle should start. I don't think I could use the same meathod because I don't think I would be able to se my lines if I use a belt grinder. So what do you guys do?
.
Click to expand...


Most makers do the exact same thing , scribe your lines for your edge ( or what you want your final edge thickness to be ) , and grinding edge up , you can still see your lines.

I know it sounds weird , and you would think the belt would yank the knife out of your hands , but it doesn't ( at least using belts with a good splice).

I have to admit , a few weeks ago I tried making a knife by hand filing... 1/2 way thru I bailed and fired up the Bader :D
 
Wether or not your flat grinding or hollow grinding once you main bevels are established it will be easy to "follow" them. So, if you mean the main bevel angles then yes, you will learn to keep them straight by eye/hand. If you start a full flat grind that goes to the top of your blade andboth come to the middle line you scribed then your angles will be solid. For a hollow or flat that only comes up the blade a ways just mark where you want the top of the grind to stop on both sides and as you get to your higher grits push the grind line up to where it belongs. If you keep the center line and your grinds are the same hiegth then your angles should match up.

If you mean the angle of the final cutting edge then again you will earn by hand/eye. I was very nervous putting a final edeg on with a belt until i did so. Just keep the knife at the same angle to the belt and go nice and slow. Lock you elbows at your sides to stabalize your hands. I put the initial cutting edge on with a 400 and then use and old 800 belt that has no grit left on it charged with green rouge to take of the bur and put a final edge on.
 
You must log in or register to reply here.
Back
Top