O1 vs D2

[OconeeDan]

Tinkering with different carbon steels for blades.  This is a question about stock removal blades, not forging.
So...pros and cons, of O-1 vs D2?
Thanks in advance.  Dan

[Ian johnson]

D2 you need to work at it to get it sharp, but once you do, it stays there!

[robtattoo]

D2 needs specialist heat-treatment (If my meory's correct) including a cryo-dip. 01 can be simply done in the oven. I have never really been able to understand why folks seem to prefer D2 over 01 blades. It seems like a lot more work to acheive the same results.

[OconeeDan]

Hmmm, Rob.  According to Jantz , D2 simply needs to be treated, no cryo dip mentioned.  They say to treat at 1850F, then air cool.  Then temper.
For O-1, they say to treat at 1450-1500, then quench in oil at 125-150F, then temper.
Hope someone else chimes in.
But it seems like you like O-1, correct?
I have used D2 (and I like it), but I had someone else treat it before I got an oven.
O-1 is much cheaper than D2, which is why I asked in the first place.  If O1 is as good as D2, then why use anything else?
Thanks, Dan
ps-Rob, are you still planning to come here next year?

[BobT]

O1 is what I use to make most of my knives. I have never made one from D2 but I have heard it praised for edge holding ability. I use O1 for a couple of reasons. The blades I make are mostly thin (1/8" thick or less) and O1 is not as likely to warp as some of the other steels. I can get satisfactory results heat treating with a torch and a can of olive oil, and I can buy it from work in pretty much any size I need.

[Emmons]

Never work with D2 or O1.  All my knives so far have been made from old files which I believe is W1.  But I have done a lot of reading about both D2 and 01.  Dan you are correct that the cryogenic treatment is not necessary with the D2.  The cryo is suppose to raise the hardness a point or two and is done between the first and second tempering cycle.  

This is what Crucible said “Cryogenic Treating: Refrigeration treatments may improve long term dimensional stability by transformation of retained austenite. Refrigeration treatments should generally be performed after the first temper, and must be followed by a temper”

Also D2 would be difficult to work in a forge, an oven is required.  This is because you have to hold the temperature at different times.  It is recommended that you preheat during hardening and also hold the hardening temp for 20 to 30 minutes.  During the tempering cycles which are done at higher temperatures, is held for a longer period of time.

In my opinion the biggest benefit of D2 is the resistance to corrosion.  Some call it a semi-stainless.  Some also say it has better wear resistance.  But you can get 01 or W1 to the same hardness levels with less equipment.

Hope the is helpful,

James

[Emmons]

I was just poking around the Crucible web site and they said the same thing about the cyro for D2, A2, 01, and L6.  These are the only knife steel they make.

[Tim Fishell]

The biggest difference between the tool steels is the process in which they are hardened.  O-1 is heated and then oil quenched, A-2 and D-2 are heated and then air hardened or tempered as they cool.  I have never made knives so I am not sure what hardness is best for sharpening and maintaining an edge but I would think it would be a fine line.  I am a design engineer in a Tool and Die shop so we use lots of different tool steels for different applications.

[Otto]

Ray Charles could make a knife outta O-1.

Bob Dozier's the only guy I know that knows how to properly heat treat D-2.

[Wampus]

O1 is a lot easier for the home shop guy with minimal equipment, but there's no big mystery to  heat treating D2 if you have a proper heat treating oven.  The info is available from most of the steel companies on their websites.   http://www.crucibleservice.com/datash/ACFC3C.pdf?CFID=2030988&CFTOKEN=18788421

[OconeeDan]

Now this has been a beneficial discussion for me, thanks for all the good information.
I do have an oven, and can heat treat either steel.
The price of O1 is significantly less than D2, I was wondering if the performance of D2 was worth the extra cost.
Thanks, Dan

[Leftieshot]

What kind of oven did you end up with?
As far as D2 beiong worth the extra cost, thats something only you can decide as a maker.

[OconeeDan]

I bought two very old furnaces, one is a little Paragon that is only large enough for pocket knives and small parts.  The other is an old Hoskins, large enough to do anything 12" and shorter.
Dan