Forging A2 and D2

[JTknives]

Well with how the economy is and with the problems crucible is having i have been thinking about how i need to really stock up on good knife steel. i have a local surplus store that always has A2 and D2 in large rounds at something like .30-.45 a pound and i have like maybe 150 pounds of those 2 right now plus 126 pounds of L6 and 70 Pounds of S7 and about the same of O1. and i am wondering What i need to be aware of when forging these (A2 / D2) down. i have a pid controlled forge so temp holding is not a problem. what is a good temp to forge these at and any other tips you might have. I wonder this as my budget would allow me to stock up and be set for life at those prices but its all mostly very large rounds that have to be cut up and forged. Thanks every one.

 

[Chuck Gedraitis Knives]

Seeing as they are both air hardening steels you are going to have to forge them hotter than usual and the working time will be shorter.

I think you might just waste your time.

 

[Troop]

JT, I forge A2 quite a bit, and it kicks ass, if you do it right.
Here is a good spec sheet from Carpenter
http://cartech.ides.com/datasheet.aspx?i=103&e=262&c=techart
Don't forge below an orange color, approx. 1700 F, or you risk cracking the steel.
Also, you have to watch the retained austenite issue; I take Steve Hayden's recommendation and use 4 temper cycles to take care of the problem.

 

[mete]

Both A-2 and D-2 are forged between 1850 and 2000 F.Both should be preheated , especially D-2 since the high Cr lowers conductivity.Both should be slow cooled , not normalized.Anneal before machining.

 

[galadduin]

Forging D2. I have bad memories of it. I used to have some 7 mm stock and used to thin it down to 4mm, for a 5" blade I used to spend hours of hammering, usually ending up with a cracked piece....
It is stubborn, doesn't get shape like a carbon steel, very narrow forging temps, you have a couple hammer blow chance per heat if it is not thin, as it gets thinner it is virtually impossible to hit, it cools under the forging limit in a couple seconds before you lay it on anvil....
Just nightmare.... I bought a large plate of 3.5mm stock of it, measuring 1 mt x 1 mt. Now it is fun just to cut a blade from that plate and start grinding. I had real rough time to find this stock but if you order a large plate like me you'll be able to find a supplier for it. They just don't want to deal with small orders...

 

[Steve Hayden]

I have been forging A2 for the last 2-3 years. Mete has it right-don't forge too cool or it will crack. I pinged the tip off of the first blade I forged from it. I cut off the cracked part and finished it and have been using it ever since as my hunting knife.

Be sure and do a good strain relief heat 1200°F+ for 2 hrs and bring the temp down slowly slowly to 900°F over a couple more hours. I do this after forging and before grinding.

Like with many steels, I can't prove forging makes a better knife, but I like the blade shapes I get better. Round bar is very reasonable from flatground.com. For hand forgers like me, 11/16 to 3/4 round makes a good size to work with.

I have been using the Bohler/Uddeholm datasheets for technical info on the tool steels for the detail they provide.

 

[Sam Salvati]

Well with how the economy is and with the problems crucible is having i have been thinking about how i need to really stock up on good knife steel. i have a local surplus store that always has A2 and D2 in large rounds at something like .30-.45 a pound and i have like maybe 150 pounds of those 2 right now plus 126 pounds of L6 and 70 Pounds of S7 and about the same of O1. and i am wondering What i need to be aware of when forging these (A2 / D2) down. i have a pid controlled forge so temp holding is not a problem. what is a good temp to forge these at and any other tips you might have. I wonder this as my budget would allow me to stock up and be set for life at those prices but its all mostly very large rounds that have to be cut up and forged. Thanks every one.

JT, what size rounds are we talking? Have you ever forged 1 1/2 by hand down to even 3/8ths by 1 1/2? Do you have a power hammer? Big steel like that is nice unless and everyone think's it's cool you can get so much for so cheap, but if you can't do anything with it, THEN IT'S NOT SO NICE ANYMORE AND IS JUST A WASTE OF SPACE, until you can handle it of course which might be 5-10 years down the road or never. Unless you are slicing it up into more manageable slices (yeah cutting 1 1/2 inch round bar LENGTHWISE is real whole lot of fun) the only other option would be to forge it. So you could buy a nice heavy duty bandsaw for a couple grand, or try and find a powerhammer for a 4000$-10000$ with another 2000$ for setup (for a hammer to be able to forge some of the dimensions you have there) and then you can finally get down to making that one knife for 300$ to 600$.

 

[Nowicki]

I like forging D2. Like said before you have to forge it hotter. I like the round stock. Flat stock has always given me trouble. they make great blades when done right.

Larry

 

[JTknives]

JT, what size rounds are we talking? Have you ever forged 1 1/2 by hand down to even 3/8ths by 1 1/2? Do you have a power hammer? Big steel like that is nice unless and everyone think's it's cool you can get so much for so cheap, but if you can't do anything with it, THEN IT'S NOT SO NICE ANYMORE AND IS JUST A WASTE OF SPACE, until you can handle it of course which might be 5-10 years down the road or never. Unless you are slicing it up into more manageable slices (yeah cutting 1 1/2 inch round bar LENGTHWISE is real whole lot of fun) the only other option would be to forge it. So you could buy a nice heavy duty bandsaw for a couple grand, or try and find a powerhammer for a 4000$-10000$ with another 2000$ for setup (for a hammer to be able to forge some of the dimensions you have there) and then you can finally get down to making that one knife for 300$ to 600$.

I forge down 1" round L6 with no problem by hand. I have a press that i use to get large stock down to a useful size. i use the liquid cooled auto feed band saw at work to cut up my stock. i cut up a round that was 6.5" wide x 7" into 5/8" by 1" by 7". and cutting up the whole round only took me a few hrs of time. and as i work very ate there i end up having the shop to my self and that's when i do my cutting. so most likeley the 2.5 rounds i have i will split length wise into quarters and about 15" or so inches long.

 

[Raymond Richard]

D-2 and L-6 are two different things. I will admit there were a few years of my life when I thought I had super human powers and I forged down some 5/8 round D-2. I may have even been using a 10 pound hammer then and it still barely moved. At least with A-2 you can tell the hammer hit it. I bet you still had to really work to forge out the 1" L-6.

 

[JTknives]

D-2 and L-6 are two different things. I will admit there were a few years of my life when I thought I had super human powers and I forged down some 5/8 round D-2. I may have even been using a 10 pound hammer then and it still barely moved. At least with A-2 you can tell the hammer hit it. I bet you still had to really work to forge out the 1" L-6.

Ya it was still quite a bit of work, but i still have my super powers . i dont have much D2 but i thought i would pick up some just because. now how is A2 compared to crucibles L6 in forging

 

[Troop]

Ya it was still quite a bit of work, but i still have my super powers . i dont have much D2 but i thought i would pick up some just because. now how is A2 compared to crucibles L6 in forging

JT, Make no mistake about it; A2 is a bitch to forge. It seems like it gets harder with every heat...and maybe it does.

 

[deker]

I forge down 1" round L6 with no problem by

Now, go try and forge down even a piece of 1 1/2" mild...it's a different beast entirely. Don't forget your geometry! 1" round 6" long is about 4.7 cubic inches of material. 1 1/2" round of the same length is more than 10 cubic inches of material....

-d

 

[Steve Hayden]

Ya it was still quite a bit of work, but i still have my super powers . i dont have much D2 but i thought i would pick up some just because. now how is A2 compared to crucibles L6 in forging

I haven't forged L6, but A2 is a bit stiffer than 52100 millballs.

 

[Stacy E. Apelt - Bladesmith]

JT, You have enough steel on hand for a couple thousand knives, so you really don't need more steel. You have sizes that are unfriendly to work with . that is a bigger problem. Once your hands heal from your recent accident, you will be ruining them again if you try to forge down large round stock.( ask raymond about bad hands and joints)
Slice up what you can, since it is at no cost beyond time. Forget forging the big and hard stuff for a long time. You will need a much more robust and faster press ( or a power hammer) than the one you built recently to do much with 2.5" A-2.
If you forge it too cool, most air hardening steels will be ruined. It may not show until the HT, or later, but it will come back to bite you if you don't watch the temps closely. The strike time for A-2 and D-2 is short. I personally don't consider either a forging steel.
BTW, pre-heat the anvil.
Stacy

 

[JTknives]

Update, i know I'm a bit late . I was the shop the other day because my flatmate needed to work on his car. So I started up the forge and looked for some steel. I found a chunk of A2. I was expecting a nightmare, but I was supprized. It was not all that bad, it would of course get hard if let to get to cool. I just worked it at 2100 with a 4 pound hammer and it formed well. I will be finishing the blade this weekend.

 

[Ed Fowler]

Things sure change: Just a few years ago this would have proven to be a highly controversial subject. Way to go gentlemen!