Q: I’m a little confused on the difference between ASTM A193 and ASTM A194? They seem to both cover stainless steel 316 and stainless steel 304.
A: The difference between ASTM A193 and ASTM A194 is not in the materials they focus on, but the type of fasteners. ASTM A193 covers bolts for stainless 316 Grade B8M, 304 Grade B8, and 4140/4142 Grade B7. In contrast ASTM A194 covers the same materials but is a specification for nuts.