UNS Numbering System

Date 10-25-2001 12:07

If I tell you the S stands for Stainless Steel, I bet you will say I knew that!
S31600
From there you have 316 SS just like the AISI 316 which equates to a lot of other Societys like ASME SA182, ASTM A167 and AMS 5507.

N is for Nickel Alloys
N06625 recognize the 625 as in INCo 625

L is for Low melting metals and Alloys
K is Miscellaneous Steels and Ferrous Alloys
H is AISI and ASE H-Steels
J is Cast Steels except Tool steels
G is AISI and ASE Carbon and Alloy Steels
E = Rare Earth
C= Copper and its Alloys
A= I bet you figured this one out already (Aluminum in case some else who didnt know is reading)
F= Bet you knew that ones for Cast Iron already
P for Gold and ohter Precious metals
Z for Zink and Alloys
T for Tool steels
W for welding rod
R is Reactive and Refractory metals and Alloys

I dont think I missed any, Hope this helps

By dasimonds (**)

Date 10-26-2001 04:00

Thank you gentlemen,
Your right, Ron. I did know S was stainless and N was Nickel.
But that was it. I don't have much experience with the code and paperwork side of the welding business, so please don't assume I know anything about it.
Tell me, in the case of S31600, what do the extra zero's stand for?
And the extra 06 for N06625?
Dale Simonds

By RonG

Date 10-26-2001 15:33

As near as I can tell its just a 5 digit system, in the index it gives the Alpha symbol then 5 X's.

Okay darn it I read the whole thing and it looks like I guessed right.

"Although some of the digits in certain UNS designation groups have special assigned meanings, each series of UNS designations is independent of others in regard to the significance of digits, thus permitting greater flexibility and avoiding complicated and lengthy UNS designations."

Pretty long sentence if you ask me.

By G.S.Crisi (****)

Date 10-26-2001 22:56

Thank you very much, Ron, I've learned the fundamentals of the UNS, which I didn't know. According to your explanation, zero is the number which is included when there's no reason to include any other number.
Giovanni S. Crisi

By dasimonds (**)

Date 10-28-2001 12:15

Ron,
Great so far. How about UNS itself. United Numbering System perhaps?
Professor Crisi,
I see you've reduced the statement down to it's simplest terms. Thank you. If I might ask, how did you glean that from the quote Ron gave? If I knew how your thinking, I would help me to understand this complicated code language. I must admit, this kind of language looks like Latin to me. "each series of UNS designations is independent of others in regard to the significance of digits..." . The only meaning I get from this statement is there is no system, at least not in the sense one might expect, as with the numerical breakdown of welding electrodes, at least for someone with limited experience as myself. I'd have to agree with Ron, it looks like a pretty long sentence. Any ideas to help me with this?
Dale Simonds

By RonG

Date 10-29-2001 13:36

I will try to float a theory and avoid reading the intire code SAE J1086 Revised Jul95.

There are a great many duplications of alloys each with a different code designation or different designation in the same code.

In UNS system there are some alloys with as many as 50 cross references in ASTM, AISI, ASM, ASME, MIL SPEC, FED, AMS & etc.

There may be 10 -20 ASME and the same in ASTM and ASM.

To get a UNS number an alloy has to be a "Commercial standing product" with 2 or more producers with a combined production of 200 tons per year.

So it seems all equivilent alloys come under that number.

At the moment thats all the wisdom I see in it, I will continue to study as time permits and get back to you if you really want to know.

By dasimonds (**)

Date 10-29-2001 13:45

Ron,
I think you've given us enough information about the UNS system already. Thanks for the effort. I'm satisfied.
Dale Simonds

By - Date 10-29-2001 18:06

Just to expand on your thoughts here.

The UNS system appears to me to be the American equivalent of the German Werkstoff system. Here the system is based only on the material's chemical composition and mechanical properties. (As far as I can see.) Most of the other systems are also dependent on the product form and end use.

Regards
Niekie

By chall

Date 10-25-2001 12:10

Mr. Simonds, there is a cross reference book that gives material specs based on UNS. N06625 is an Inconel 625 material, ASME spec SB-443, 444 and 446. GTAW filler is covered by SFA 5.14 (ERNiCrM0-3. The base metal is an ASME P-43, filler F-43. S31600 is an austenitic Cr-Ni-Mo stainless. ASME spec SA182 grade 316. There are a number of other specs also listed. If you want more just let me know. Charles Hall.