ASTM (American Society for Testing and Materials)
A group of scientists and engineers formed the American Society for Testing and Materials in 1898.
ASTM International (ASTM), is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services
ASTM predates other standards organizations such as (1901), DIN (1917) and AFNOR (1926), but differs from these in that it is not a national standards body.
ASTM A193 / A193M Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for High Temperature or High Pressure Service and Other Special Purpose Applications
ASTM A320 / A320M Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for Low-Temperature Service
MATERIALS- HEX NUTS
High /Low temperature service
ASTM A194 / A194M - 09 Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or Both.
MATERIALS- STUDBOLT/HEX NUTS
ASTM A453 / A453M Standard Specification for High-Temperature Bolting Materials, with Expansion Coefficients Comparable to Austenitic Stainless Steels