D2 or BG42

Mar 22, 2001
Hey Guy's,i've been a lurker for a while and just recently became a member so here's my first post!!! I'm trying to decide which steel to use for a folder with a blade just under 3.5'' and 5/32'' thick,i'm a Firefighter/Paramedic so it's going to be a hard user, light prying and alot of cutting, can you give me the pro's and con's between the two ?? I'm leaning toward's the BG42, but i hear that D2 is a great steel also. Can you give me your opinion's so i can make up my mind ?? Thank's Mario C.
Aug 25, 1999
There are many, many others here that know much more about this topic than I do, but I'd like to give you a couple things to think about.
I believe that the D2 would be better with the light prying/strength category, however being a firefighter the knife is likely to get wet and there's no telling how quickly you would be able to attend to it. This would give BG42 the edge.
You specified a folder which indicates that brute stength is not a priority. I would therefore suggest BG42. It is very strong, just not quite as strong as D2 in my opinion. It holds an edge very well, and is easy to sharpen.
Probably the most important factor regardless of which steel you choose is the heat-treatment. This variable is controlled only by the man who makes your folder. I'd suggest doing extensive searches here on BFC to see who has the best reputation for heat treating the type of steel you choose.
(if you don't get the response you're looking for here, I'd post this question in the Shop Talk forum where the makers hang out. You might also email Cliff Stamp as he is the resident strength-testing expert.)
Good luck!
Aug 4, 1999
I'm glad to see you joined in!!
You already know that I'm a D2 NUT so I'll leave this discussion with that

Please say HI to the other half,


Hand Made Knives..High Tech Materials


Jun 30, 1999
Neil! [Dr. Lathe]
Do you have any BG42 or D2 folders in the works? If the folders are anything like your straight knives,the're superb and sound perfect for firefighting, among other things.

[This message has been edited by HJK (edited 04-13-2001).]
Jul 2, 2000
Look at the Buck #532 in BG-42!

Bremerton, Washington
Mar 22, 2001
Hey guy's,thank you for the responses !!!
Paul,i e-mailed Cliff,Good Idea !!
Neil, hi back to you and i knew what your answer would be,hope everything is well !!!
HJK,I would be the first person in line to buy one of Neil's folder's,sorry to say it's not from him!!
Ron,i see what you mean and i like your dog!! If any one else has an opinion on this subject,please feel free to post it !!
Thank's again, Mario C.

Cliff Stamp

Oct 5, 1998
One of the advantages of BG-42 as a blade steel is that it has a very high max hardness. Sog for example is using it at 62 - 64 RC. Compare this with 440C which drops under 60RC readily when tempered. What the high hardness gives is high resistance to impaction (which is basically exactly what hardness measures) as well it will be very strong and thus the edge will resist rolling well.

BG-42 also has good heat resistance, which while not overly important for most people would seem to be inline with your profession. However the kind of heat necessary to overly effect the performance of most blade steels (causes a drop in hardness) I would think would effect the handle materials, unless you are seeing a once piece stainless construction.

In any case both steels you mention are very high alloy steels and thus are *very* strong and wear resistant. Both will allow a high max hardness (D2 about 62 and BG-42 about 64 RC). One downside is that both are decently expensive in terms of cost of stock and in terms of working, grinding as well as heat treats. You want multiple tempers and/or cryo to get max performance. However those kinds of things are generally the makers problem not yours, except for the price they result in anyway.

The downsides for these allows is that they have a low impact resistance and ductility. For a pure cutting blade I would not be concerned about this as the worst you will see is a hard impact off of an inclusion (staple or dirt or something) and because you are generally relaxed and cutting smoothly with low force all you will see, even with a very thin grind (0.01" thick behind the edge) is a small chip about 0.0025" - 0.005 " deep.

However for high stress work when you could be putting a significant amount of force on the blade in less than a well controlled manner, especially twisting during a cut which is hell on an edge, I would want a steel that was high in impact toughness and ductility to insure than the damage does not functionally effect the blade.

The toughness insures that it will not shatter it you hit it with something or hit if off of something with a lot of force. The ductility gives you a lot of protection when prying. You have to induce a large flex before fracture which warns you that you are approaching a critical point.

I would suggest something like CPM-3V, it has a wear resitance similar to D2 but a much higher toughness and ductility. However be careful with the hardness, you can easily get 3V up to 62 RC. But again if you are prying or doing other hard work I don't think that gives the kind of properties that you would want.

The best thing you can do is be very clear with the maker about the kinds of use the blade will see. One other thing you might want to do is buy a cheap folder like the Spyderco Endura and use that for say two weeks. You can then use this as a definate baseline for the maker to work off of (I want something with a stronger tip, cuts better, more durable edge or whatever etc. .)

One more thing, since it is a folder, and considering the kind of use your line of work seems to suggest I would be very careful about the lock type and I would strongly suggest you run the lock through a gauntlet of tests before you actually lean on it while on duty.


[This message has been edited by Cliff Stamp (edited 04-14-2001).]
Jun 6, 2000
Both are very very good steels. D2 has the better edge holding, but not as stain resistant to rust etc.

For a novice user I would use BG-42, for a more experienced user I would go with D2 and a little more looking after it!

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Mar 22, 2001
Cliff and General, Thank you for the reponse,it's really helped me out a lot,i think BG42 is what i'm going to use and Paul Bos is doing the heat treating!!! From what i hear about him and his work i think i'll be on the right track to getting one Bad A$$ folder !!!
Thank You all again and Take Care!