Steel grade designations

[thegeek574]

I recently screwed up by assuming that 52100 was close to 50100. Only later do I realize that they are not very close at all. That brings on the question: is there any rhyme or reason in the designations in steel grades? I know that 10xx steels make sense becuase they are all according to the amount of carbon that they have, but the rest of them seem rather arbitrary. Do they take the lottery number of the week that they decide on the composition and have it be the last 4 digits of that ? Thanks for clearing this up and sorry for jumping to conclusions.
Steven

 

[mete]

There is rhyme and reason ! The last two or three tell you the carbon content .In your example 100 means 1.00% Carbon .The first two give the major alloying elements : 50xxx -.40-.60Cr. 51xxx-.90-1.15 Cr. 52xxx - 1.30-1.60 Cr


http://info.lu.farmingdale.edu/depts/met/met205/steelclassification.html

This will give a brief definition of AISI numbers.

 

[thegeek574]

Sweet. What about in-house stuff like carbon V, AKA 1080?

 

[12345678910]

Sweet. What about in-house stuff like carbon V, AKA 1080?

Sweet jesus man, all you have to do is read the open threads.

what makes you think Carbon V and 1080 are the same ?

http://www.bladeforums.com/forums/showthread.php/928202-0170-6-apology?p=10535603#post10535603

Carbon V

Carbon V is a trademarked term by Cold Steel, and as such is not necessarily one particular kind of steel; rather, it describes whatever steel Cold Steel happens to be using, and there is an indication they do change steels from time to time. Carbon V performs roughly between 1095-ish and O1-ish, in my opinion, and rusts like O1 as well. I've heard rumors that Carbon V is O1 (which I think is unlikely) or 1095. Numerous industry insiders insist it is 0170-6. Some spark tests done by a rec.knives reader seem to point the finger at 50100-B. Since 50100-B and 0170-6 are the same steel (see below), this is likely the current Carbon V.

0170-6 - 50100-B

These are different designations for the same steel: 0170-6 is the steel makers classification, 50100-B is the AISI designation. A good chrome-vanadium steel that is somewhat similar to O1, but much less expensive. The now-defunct Blackjack made several knives from O170-6, and Carbon V may be 0170-6. 50100 is basically 52100 with about 1/3 the chromium of 52100, and the B in 50100-B indicates that the steel has been modified with vanadium, making this a chrome-vanadium steel. Ref - 0170-6 - 50100-B Steel Composition.

 

[thegeek574]

Whoops. I could be reasonably called 16 and senile. I meant SK5 when I said carbon 5

 

[A C Richards]

Unless you are using the AISI designation it is up to the manufacturer to name the steel. With them there can be no rhyme or reason. Some can be figured out but you need to find the site that has the list to really know what it is. Like carbon V, it was a mystery for years and still some mystique and then there is INFI. Many companies have a proprietary run done with slightly different or even the same elements as well known steels but use the slight difference as a marketing ploy to get you to buy their product. Best thing to do is try to find the chemical analysis to really know what you are getting.

 

[thegeek574]

OK. Thanks all for helping to give me good information and some confirmation of my suspicions.