51200 question

[Hurley]

If I remember correctly 52100 is ball bearing steel. Does someone know the HT properties of it? Do you need an oven or will a forge do? I know just about anythin in the 10-- family except for 1095 doesn't need very fine heat treat control. Will it make a good blade, easy to work with, etc. Yes I did a search, but I kept coming up with dead links and topics that had nothing to do with ht or workability.........lol

[Ray Rogers]

52100 is a ball bearing steel. It can be HTed in a forge but isn't the easiest steel to get right that way, an oven is better. You should be able to get the data sheet for 52100 from alphaknifesupply.com They have data sheets in pdf form for most of the steels they sell ....

[Fulmaduro]

Hey Kevin, some say it is a bitch to forge and others tell me it is not. Just not as forgiving as other steels. Must be worked hot, put back into forge when it starts to cool. HT is said to be tricky. Will produce some nice hamons. A great steel once you get it right.

I have heard all the above from very knowledgeable bladesmiths. I have yet to try it. I have a bunch of it in 1/2" round stock and plan on making some integrals with it. I will find out sometime by spring.

Tony Z
Kansas City, MO

[Doug Lester]

52100 has the same problem that most high carbon steels have. If you heat it too hot for too long you will get a build up of retained austinite which will have to be dealt with later. Others may disagree, but I think that the high carbon steel of around 1% are better dealt with in a kiln or molten salt tank. Ray's right that you might be able to heat treat it well in a forge and I think that I have done so after testing the blade to destruction but being able to do it consistently is another matter.

As far as forging goes, work it hot and stop striking with the hammer well before it loses color.

Doug

[Crex]

Doug is pretty much spot on. Little "stiff" under the hammer until you get it reduced to blade thickness and start your distal tapers. Has to be worked hot but not too hot and never cold. If you get it too hot as Doug stated it is a buggar to deal with the austinite later, very difficult if you don't have a good oven. Not a very forgiving steel.
Makes a heck of a blade when you get it right, but not something most beginners will get even close to right.
Keep in mind that most of the bearing stock available these days is not 52100 anymore. A lot turn out to be case hardened steel of dubious quality. Pretty much a simple cross sectional slice off a bearing race and etch will tell you if it's case hardened or not.
Buy from a supplier or a verified source if you want consistent results.

[jmccustomknives]

Working 52100 isn't for the faint of heart or for the power hammerless (unless one is hard headed like me). I've gotten a nice supply of new and used bearings and bar stock. I make skinners from the 1 1/4" ball bearings. It takes about 30-40 minutes with a 10lb sledge hammer just to get it drawn out into the billet. From there it is shaped with lighter hammers. As other have said, it's a little tricky to heat treat. Done right though, it makes an excellent blade.

[samuraistuart]

Here is a highly recommended HT recipe for 52100.

For normalizing/grain refining
1. 1650F for 10 minutes, cool to black, quench
2. 1350F, cool to black, quench
3. 1250F, cool to black

To austenitize
1. 1475F for 10 minutes, quench in medium speed oil (130F canola actally works very well for 52100). Temp
can be up to 1500 or 1550.

I temper at 420F for two hours.

I couldn't tell you the exact RC I'm getting, but I'm VERY impressed with this steel and this HT recipe, given to me by one of the 52100 chefs out there.

Hope this helps a bit.

[Crex]

Just for clarification - At what stage are you doing your first three steps? That might not be too effective on 1" round stock. Guessing after you have done some major reduction to knife size dimensions.

[samuraistuart]

Carl, I couldn't help but think of Travis in Taxi Driver, "You talkin' to me?". Yes, steps 1-3 would be done after forging. If forging, add these steps above steps 1-3. For stress relieving.......1650F, cool to black. To anneal, 1250F, cool to black (x2). If stock removal only, just start with the normalizing procedure in my previous post. The 52100 coming from Mr Bruno in New Jersey is about 95% spherodized, so even if only stock removal is done, the normalization procedure is a MUST for his 52100.

Thanks for asking, Carl. I meant to put that down. Have a great day guys!

[Hurley]

Sorry if my question threw some people. I am not forging knives, I do stock removal. I don't have a place to put a forge; however, I haven't had time to build one because I'm concentrating on a KMG or DIY grinder.

[Doug Lester]

Yes, 52100 will make a good knife by stock removal if you have the equipment to heat treat it like a regulated kiln or a molten salt pot or know of a heat treating service that can handle the alloy. However, I would recommend 440C over it because it will be easier to find someone who can heat treat it for your. By the way 440C is itself a bearing alloy.

Doug

[Hurley]

Thanks Doug, Ray, Crex, everyone for giving me a little "personal experience" info on the steel. That usually tells me much more than a spec sheet ever could!

[Crex]

Hey Stuart, just asking for the benefit of the thread (kind of knew the answer). The real new guys to the game seldom use inductive reasoning.
Doug is absolutely right, much easier to find someone who does 440C correctly and it's really a very fine very available blade steel. Factory knives did more to malign the steel than anything. Back in my stock removal days it was my favorite. Just doesn't lend itself to forging fun all that well. Too tight a thermal window.