Dear all, we can see some material as A 106, SA 106.
Please send me the explain why we have the defference beween SA and A?
what does SA mean? and A also?
Thanks you so much
The A specs are ASTM, and ASME does not always adopt the specs as-is. Some ASTM specs are not in the Code (no S equivalent), this is usually because they don't require mechanical testing.
There are cases where the SA requires something that is optional in the A spec.
And then there is simply the time lag from ASTM revision to ASME adoption.
If you look in the header of an ASME spec it will say 'identical to ASTM xxxxx' and tell you what spec it was adopted from. If there are changes or exceptions they will be noted.
Remember for ASTM it is always a letter linked directly to a number (e.g., A106), whereas with ASME it is two letters linked to the same number with a dash (e.g., SA-106). I have had to reject an entire draft specification I was reviewing because this was so sloppily done.
(Sorry to be pedantic, but doing things right usually requires no more effort than doing them wrong.)