Can anyone tell me how to harden and temper A D2 steel knife blade. I have torches, and a forge.

Thanks

DLH

D2 and other stainless steels and complex steels require precise temperature and time control.You must have a furnace [not a torch or forge ] that will get up to about 1950 F.Send it out to someone like Paul Bos.

DLH4570,

OK i make knives and i'll let you on on a little secret. I HT Stainless steel a lot, ATS, 440C, D2, S3v, you get the idea. i also have access to a rockwell hardness tester and liquid nitrogen. OK i'll stop with background and give you my recipe for most SS blades i use. Heat up to 1900F or 1040C in a heat treating furnace and soak for 30 mins. in SS foil. without foil you are wasting your time and ruining your work. do not try to do this with a torch you are wasting your time. OK then i quench between quench plates or 2 big pieces of metal, foil and all. cut the blad out of the foi, now the blade is fairly well hardened. I quench in liquid nitrogen if i want to 5 mins is all you need soak here does nothing for you its an instantaneous reaction at these temperatures. Some steel respond to this with a 2 point increase in hardness others don't resond. from there i temper to whatever my desired final hardness is. I like a hard blade i temper at 250F for as long as i want to in my stove oven 30 min. to couple hours overnight whatever. in other words i'm stress relieving not tempering in the true sense of the word. If i lost you or confused you in any way email me at nedozier@utep.edu. i'm a metallurgist and love to help others with heat treat (HT) issues, take care. Sorry my response got so lengthy

Another metallurgist ? very good .I spend time on a number of the knive forums trying to teach makers some metallurgy. It actually rubs off on some !! More and more are using plate quenching for the stainless steels , very convenient. Welcome to the forum.

Thanks for the welcome Mete. I've did one knife without quench plates, and that was a lot of knives ago. they are stupid proof for me.

We use salt pots for both high temp and quench temp. If blades are thin, we put them between plates immediately after the cool pot ... we have very few warped blades.

Obviously they go to cryo after that.

Drawings for building salt pots are located on this site:

our knife site

Heat treating is the soul of a blade in "The Craft" section.

Sounds like there are alot of knife makers here so I'll ask,how do I get started making knives?I have made a few kit knives but would love to make one from start to finish.I've become disabled and need an outlet for energy and I can think of no other outlet I would like better than knife making.Are there videos?Courses?Thanks Drop-Shot

Go to http://www.bladeforums.com or http://www.knifenetwork.com Do a search and you'll find all the info you need.