D2- A2 toolsteel

[hunterjntx]

This may be a dumb question but I don't know the answer. Is D2 and A2 toolsteel stainless or carbon steel.

Thanks
Jason:confused:

[jethro]

They are both a carbon steel. But D2 is a near stainless. Both are great for making knives. There are plenty of people here that can answer this much better that I can, but if you have some of these steels don't hesitate to use them.

Mike

[hunterjntx]

Thanks for the reply. The reason I asked is because I prefer the carbons steels for the way they age and color and I didn't know if the D2 would discolor like 01.

Jason

[jethro]

D2 will develop a patina. It will get a little bit of a gray look to it. It can usually be cleaned off with a good metal polish, but since it is not a true stainless, it will change color with neglect.
I believe A2 will be more likely to develop a patina similar to other tool steels. If that is what you are wanting, it may be your better bet.

Mike

[Jason Cutter]

I know a bit about A-2 but I've never used it so I won't say much. I suspect it will tarnish like any other carbon steel (which is what it is). D-2 is a great steel. It looks to have about 12% chromium which is JUUUST under the magical 14% chromium for stainlessness. But gee that steel gets, sharp, stays sharp and cuts and cuts. Great for working knives, it doesn't finish well unless you actually like the coarse-grained Wootz-like pattern on the steel. (I quite like it.) Instead of polishing which is very difficult, I satin hand rub to either 800 or 1200grit - looks quite nice.

I find that it definitely doesn't stain like the other carbon steels. But some meats, especially fish and red meats seem to tarnish it more. But on fruits and vegetables it seems to be more resistant. I wonder what others have found ?

Of the high-alloy steels, I'd pick 440C for stain resistance, D-2 for edge holding and ATS-34 for something in between.

Hope this helps. Cheers.

[BobLee]

As a begenner the following is a link to a page that has be a great help to me.

http://www.engnath.com/public/manframe.htm

Hope it helps
Bob

[whv]

that is the link from which i was remembering the phrase:

D-2 takes a lousy edge and holds it forever

a2 can be made scary sharp without too much difficulty and seems to hold an edge as well as ats-34 if the rc is up around 60, but d2 seems to hold it's edge longer. then again, it's more difficult to re-sharpen. tradeoffs.

[Jason Cutter]

Can't escape tradeoffs.

I'd mention that one of the advantages of air-hardening steels is that when hardened in temperature controlled and vacuum chamber ovens (which is how its often done commercially), there is very much reduced chances of warpage. This applies to A-2 and D-2, 440C, ATS etc. That way, the blade can be taken to just about 99% of the final finish and then just cleaned up with the same grit paper as the last one you used prior to HT. Its quite "easy" that way, but this only applies to the vacuum ovens. Many knifemakers who use this system, don't do any grinding after HT at all, except for maybe putting on an edge.

In a recent discussion, we were talking about the warpage problem on thin blades like filet knives, and the difficulties with HT of carbon steels like 1084 and O-1. I heard someone say that if a carbon steel was a definite MUST for such a knife, then it would be A-2 as it could be air-hardened with minimal chances of warpage during HT. Generally though, it seems a stainless steel would seem logical for a filet knife and 440C sounds ideal. In a simialr vein, some of my very thin lightweight hunters are made of D-2.

Thought I'd throw that one in as a specific advantage of air-hardening steels like A-2. Cheers.

[shgeo]

I noticed a while back that when I experimented with oil quenching D2 to try reducing grain size of carbides that the larger ones bentwhen I laid them down in a pan of oil. I did some research on the matter and found that steels lose almost all brittle strength during the austenite/martensite transition. I solved the problem by putting the oil in a tall container and suspending the blades until they stop smoking the oil, then finishing them off in cold water. I have had no problems with warping and the D2 will take a very fine edge with the fast crystallization. I use Turco pretreat solution from K&G, so no time is lost to unwrapping foil.

[hunterjntx]

Thanks for all the replies. I'm glad to find out that D2 and A2 are carbon steels now I don't have to heatreat the O1 I can send the A2 and D2 to get heatreated which will make things alot easier on me!


Thanks

Jason

[N House]

My first knife was from 440c.I am now into D2 one thing I have found out about it is,get most of your heavy grit scratches out before HT ,D2 gets hard and is very hard to work out the heavy grind marks.I take it to 400 grit then to Ht,then back to a x100 norax and then to a x30,then to a hand rubbed finish.
A proper Ht D2 blade gets wicked sharp and stays that way.
I found a place that makes D2 with a little higher chrome
content in it.It takes a much better finish