| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.438 INCHES |
| THREAD QUANTITY PER INCH | 14 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 1.125 INCHES MINIMUM |
| FASTENER LENGTH | 2.500 INCHES NOMINAL |
| MATERIAL | STEEL OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | GM 255M,GENERAL MOTORS CORP MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | ZINC OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | 4252-M FSCM24617 MFR REF SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 95.0 ROCKWELL B MAXIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 55000 POUNDS PER SQUARE INCH |
| MINIMUM YIELD STRENGTH | 40000 POUNDS PER SQUARE INCH |
| HEAD STYLE | BUTTON |
| HEAD DIAMETER | 0.907 INCHES MINIMUM AND |
| 0.959 INCHES MAXIMUM |
| HEAD HEIGHT | 0.219 INCHES MINIMUM AND |
| 0.239 INCHES MAXIMUM |
| NECK LENGTH | 0.219 INCHES MINIMUM AND |
| 0.250 INCHES MAXIMUM |
| NECK WIDTH | 0.431 INCHES MINIMUM AND |
| 0.452 INCHES MAXIMUM |
| NONDEFINITIVE SPEC/STD DATA | C-2 TYPE |