What is ASTM A325 standard?
The American Society for Testing and Materials (ASTM) is in charge of establishing standards for various tools and industries. Although these standards are voluntary, most fabricators follow them as it increases customer trust. The A325 standard, in addition to ASTM A563 and A194, applies to heavy hex structural bolts. This standard specifies the mechanical properties of bolts with diameters ranging from.5 to 1.5 inches. A325M, the equivalent metric standard, defines mechanical properties for bolts having M12 to M36 sizes. The ASTM A325 designation was replaced in 2016 by ASTM F3125. However, the markings on bolt heads remain the same to avoid confusion.