AASHTO to ASTM Conversions

AASHTO is an acronym for American Association of State Highway and Transportation Officials. It is common for bolt specifications to be called out on construction plans with an AASHTO designation for state highway projects. Many of these designations can be directly converted to an ASTM equivalent. These are some of the more common fastener related specifications and their ASTM equivalents.

AASHTO GradeASTM EquivalentDescription
M-111A123Hot-dip galvanizing of iron and steel products
M-164A325Structural bolt
M-183A36Raw material, low carbon steel
M-222A588Raw material, weathering steel
M-223A572Raw material, high strength low alloy
M-232A153Hot-dip galvanizing of fasteners
M-253A490Structural bolt
M-291A563Nut specification possessing many grades
M-292A194High strength, heavy hex nut
M-293F436Hardened washer
M-314F1554Anchor bolt specification with 3 grades