What do the letters at the beginning of an ASTM standard signify?
Every ASTM standard is identified by a unique designation. It includes a capital letter (A – H), followed by a serial number ranging from one to four digits, a dash, and finally the year of issue. For example, a common bolt specification is A449 – 07a, although when specified the standard’s year designation is usually not included.
The alphabetical letters represent general classifications. Outlined under each classification are a number of standards for a variety of products, materials, testing processes, and many other topics.
General ASTM Classifications
- Ferrous Metals
- Nonferrous Metals
- Cementitious, Ceramic, Concrete, and Masonry Materials
- Miscellaneous Materials
- Miscellaneous Subjects
- Materials for Specific Applications
- Corrosion, Deterioration, and Degradation of Materials
- Joint Committee and District Recipients
could you please tell , when to use ‘TYPE’ and when to use ‘Gr’
For example, in case of SA 240 GR304 OR SA240 TYPE 304. I have seen both the designations. Is there any specific criteria?
Expect your reply.
@Ajith Kr – I do not believe that one or the other is correct nor incorrect, however in the ASTM A240 standard, the specific alloys are referred to as “Types”, so I believe that to be more common.