Heat treatment and arrises

Re: Heat treatment and arrises

bill tindall

>When we treated 3V we were told that alteration would be about 0.003 deep. that seems insignificant for your case. We didn't worry about it on our dovetails chisles. It is not like the steel becomes mushy, it just doesn't have the full properties. Grind the bevel down to leave about a 1/16 to 1/32 flat on the end. We ground the rest to finish shape and we saw no problem after heat treating.

Thanks Bill

Frank D. in Montreal

>That's exactly what I wanted to know.

Frank

Re: Heat treatment and arrises

fkrow

>It all depends upon how the heat treatment is performed. The main concern is in open atmosphere, the high temperature allows carbon atoms to combine with oxygen in the air. This forms a thin layer of decarburized iron on the surface of the steel, it is scale in some steels or if thin commonly called "decarb".

This is the opposite of case hardening where a thin layer of carbon is introduced to give a enhanced Rc hard layer (skin).

If the heat treatment is done in a modern furnace with nitrogen or other gas the oxygen will not be present and the decarb will not form. This is called an atmosphere furnace.

Some home workshops also will use a foil of stainless steel, wrap the part with folded over edges and it becomes protected from the oxygen and decarb will not take place. Industrial supply houses have stainless steel foil available.

I would grind to finished edges and heat treat with foil wrap or send out to commercial atmosphere furnace treatment, another final grind to clean off the discoloration.

Seriously consider commercial treatment,,,the time temperature curves are much more precise with tool steel alloys than simple high carbon steel. You will have much more predictable results and it is not very expensive.

Regards,

Fred Krow

Heat treater recommendations?

Sandor in Boyds, MD

>Do you have contact info for any commercial heat treaters that you would recommend for treating small batches of A2 steel? (chisels & plane blades)

Thanks,

Sandor (who's got a bunch of parts but hasn't had then heat treated yet...)

Re: Heat treatment and arrises

Frank D. in Montreal

>Fred,

Thanks for the info, that's exactly what I had in mind. I could handle small pieces of O1, but A2 I'll leave to someone who knows what they're doing and who has the technology to do it right.

Sandor, I don't know in your area, but around here (Montreal) you can find heat treatment pros in the yellow pages (under "Steel-Heat Treatment"). The place where I bought the steel also gave me a number (that's where I'm going to go).

Frank

Re: Heat treater recommendations?

fkrow

>Here is a URL to Thomas Register,,,I suggest finding someone close to your location and visit them,,,explain what you want to accomplish. The first person connection is nice to have,,,, you have invested a lot of hours into the project and it should be done correctly. The commercial heat treat companies normally have a minimum order price to cover costs,,,,the smaller local connection may hold your parts until another customer has some A2 and you can save on cost.

http://www.thomasregisterdirectory.com/heat_treating_services/

Regards,

Fred Krow

Heat treater recommendation

Steve Elliott

>I've had excellent service from Paul Bos Heat Treating. We did business through the mail and over the phone. He only treats air-quenched steels (A2, D2, CPM 3V, etc) but his prices are good for small batches and single blades.

Last time I had blades treated he charged $70 for a batch of up to 20 blades, and would treat smaller numbers of blades for $14 each until the total reached $70.

If you can batch your blades with others to have 20 pieces treated for $70, the price per blade is only $3.50.

His address is:

Paul Bos Heat Treating

1900 Weld Boulevard

El Cajon, CA 92020

shop (619) 562-2370, office (619) 449-1100 ext. 211

He's going to be moving his shop soon, and won't be accepting new blades after December 10. A month or two later he'll be opening his business again in Post Falls, Idaho.

Some treating tips

jimreed@marietta

>Here are some tips:

1=Deal with the same company and get to understand their processes. It will lead to more consistent results.

2=Put some scrap (of the stock you are using) in your batch and use it as a test marker. It is always good to test the batch for hardness after treating.

3=Use a spreadsheet to identify all items in your batch. Someday it will come in handy.

Good luck.

Thanks Jim, but

Frank D. in Montreal

>is there any way to test for hardness without a Rockwell tester? I don't have one and it's not too high on my list of tools to buy... Thanks for the tips.

Frank

Re: Hardness testers *LINK*

Pam Niedermayer - Austin, TX

>Frank, I've seen a set of hardness testing files. Apparently the way they work is your tool will not succumb to a file that's less hard. I've never used any of these.

BTW, do a google search for "hardness testing files" to find a pile of listings.

Pam


Hardness testing files

Hardness Testing

jim_reed@marietta

>Most hardness testers are out of my price range, but the already mentioned files are a good place to start. I do my testing by using references and a carbide tipped marker. The scratches are pretty consistent. Files are a good reference for too hard and good pocket knife blades are a good reference for almost hard enough. Stanley blade is good reference for too soft. Good luck.

Thanks Pam & Jim

Frank D. in Montreal

>

Re: Heat treatment and arrises

steve knight

>I gind them to and edge before heat treatment. the only problem it causes is the back has a little bit of warp in it. so it takes a little mroe effort to flatten. sometimes the edges get nicked in heat treating though.