Heavy hex nuts are slightly larger and thicker than finished hex nuts. There are numerous grades and the heavy pattern is typically used for large diameter and high strength bolts.
| STANDARD - ASTM A194 |
|---|
| Grade | Thread Series | Diameter | Material |
|---|---|---|---|
| 2H | UNC | 1/4 TO 2 1/2" | CARBON |
| 2H | UNF | 1/2 TO 2 1/2" | CARBON |
| 2H | 8UN | 1 1/8 TO 4" | CARBON |
| 2H METRIC | M | M12 TO M24" | CARBON |
| 2H METRIC | 8UN | 1 1/8 TO 1 1/2" | CARBON |
| 2H SLOTTED | UNC | 1/2 TO 1 1/2" | CARBON |
| 2H SLOTTED | 8UN | 1 1/8 TO 2 1/2" | CARBON |
| 2HM | UNC | 3/8 TO 1" | CARBON |
| 2HM | 8UN | 1 1/8 TO 4" | CARBON |
| 3 | UNC | 3/8 TO 1" | 501 |
| 3 | 8UN | 1 1/8 TO 2" | 501 |
| 4 | UNC | 1/2 TO 1" | CARB. MOLY. |
| 4 | 8UN | 1 1/8 TO 2 3/4" | CARB. MOLY. |
| 6 | UNC | 3/8 TO 1" | 410 |
| 6 | 8UN | 1 1/8 TO 2 3/4" | 410 |
| 6F | UNC | 1/2 TO 1" | 416 |
| 7 | UNC | 3/8 TO 2" | 4140-4145 |
| 7 | 8UN | 1 1/8 TO 3 01/2" | 4140-4145 |
| 7M | UNC | 1/2 TO 1" | 4140-4145 |
| 7M | 8UN | 1 1/8 TO 4" | 4140-4145 |
| 8 | UNC | 1/4 TO 1 3/4" | 304 |
| 8 | 8UN | 1 1/8 TO 2 3/4" | 304 |
| 8 METRIC | M | m12 TO M24 | 304 |
| 8 METRIC | 8UN | 1 1/8 TO 1 1/2" | 304 |
| 8A | UNC | 1/4 TO 1" | 304 |
| 8A | 8UN | 1 1/8 TO 2 1/2" | 304 |
| 8 STRAIN HARDENED | UNC | 3/8 TO 1" | 304 |
| 8 STRAIN HARDENED | 8UN | 1 1/8 TO 1 1/4" | 304 |
| 8C | UNC | 1/2 TO 1" | 347 |
| 8C | 8UN | 1 1/8 TO 2" | 347 |
| 8F | UNC | 1/4 TO 1 1/4" | 303 |
| 8F | 8UN | 1 1/8 TO 1 1/2" | 303 |
| 8M | UNC | 1/4 TO 1 3/4" | 316 |
| 8M | 8UN | 1 1/8 TO 2 1/2" | 316 |
| 8M METRIC | M | M12 TO M24" | 316 |
| 8M METRIC | 8UN | 1 1/8 TO 1 5/8" | 316 |
| 8MA | UNC | 1/4 TO 1" | 316 |
| 8MA | 8UN | 1 1/8 TO 2 1/2" | 316 |
| 8M STRAIN HARDENED | UNC | 3/8 TO 1" | 316 |
| 8T | UNC | 3/8 TO 1" | 321 |
| 8T | 8UN | 1 1/8 TO 1 1/2" | 321 |
| STANDARD - ASTM A453 |
|---|
| Grade | Thread Series | Diameter | Material |
|---|---|---|---|
| 660B NR | UNC | 1/2 TO 1" | A286 |
| 660B NR | 8UN | 1 1/8 TO 2" | A286 |
| 660D | UNC | 1/2 TO 1" | A286 |
| 660D | 8UN | 1 1/8 TO 2" | A286 |
