AASHTO is the 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. Often these designations can be directly converted to their ASTM equivalent. These are some common specifications and their ASTM equivalents.
| AASHTO Grade | ASTM Equivalent | Description |
|---|---|---|
| M-111 | A123 | Hot-dip galvanizing of iron and steel products |
| M-164 | A325 | Structural bolt |
| M-183 | A36 | Raw material, low carbon steel |
| M-222 | A588 | Raw material, weathering steel |
| M-223 | A572 | Raw material, high strength low alloy |
| M-232 | A153 | Hot-dip galvanizing of fasteners |
| M-253 | A490 | Structural bolt |
| M-291 | A563 | Nut specification possessing many grades |
| M-292 | A194 | High strength, heavy hex nut |
| M-293 | F436 | Hardened washer |
| M-314 | F1554 | Anchor bolt specification with 3 grades |