Are these Bearing races 52100

[Johnbeck180]

I ran across some Bering races today. Is there any way to find out if their 52100? Their made in china and the number on them is LM48510. Thanks.

 

[Salem Straub]

If there is a lot of them, it's a good deal or free, and you really want to know for sure, you can have them metallurgically analyzed. It's expensive.
I don't know what alloys the Chinese use in bearings. Maybe if your Google fu is strong you can find out.
If you want to try process of elimination, here's some ideas.
Are they rusty? If not, sand a bit of the surface of one and spray it with salt water. Wait a day or two. If it has rusted more than maybe just a tiny speck here and there, it's probably not stainless.
If it's not stainless, cut a small coupon (1/4" thick slice) out with an abrasive wheel. Scratch test the steel under the surface (middle of the cut) if a steel scribe or file will easily cut it, probably it's a case hardened bearing race.
If this test proves inconclusive, or if the center of the cut won't scratch, evenly heat the coupon up a bit past non-magnetic and quench in light oil. Grind some of the surface down to good clean metal again and try to scratch it again. If it's hardenable steel, it will probably be very hard and brittle now. Try to snap it in a vise. It should snap almost like glass and when examined inside, the broken edge should exhibit a fine non-porous grain.
If it does harden, snaps brittle and with a fine grain, and is not stainless, it may be 52100 or a Chinese equivalent. Like I say, I don't know what they use over there.
If it looks very promising after testing, make a few knives out of it, heat treat them like 52100, and destruction test them.

 

[Drew Riley]

You might try getting in touch with the manufacturer. A little more difficult being that they are based in China, but you never know.

 

[mete]

And when the Chinese say '52100' you might actually get steel but you'll never know what type !!

 

[james terrio]

I'd be pretty surprised it was real 52100. Even if it is, you'll have to forge it out flat, stress-releive it, and end up with fairly small pieces (unless they're huge races, which only means more work). What's your time worth?

52100 does make excellent knives, and new, clean, straight, flat stock isn't very expensive. New Jersey Steel Baron and Alpha Knife Supply both have some in various sizes listed on their websites.