| THREAD SERIES DESIGNATOR | UNC |
| NOMINAL THREAD DIAMETER | 0.138 INCHES |
| THREAD QUANTITY PER INCH | 32 |
| THREAD CLASS | 2A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.250 INCHES MINIMUM |
| FASTENER LENGTH | 0.250 INCHES NOMINAL |
| MATERIAL | STEEL COMP 302 OR |
| STEEL COMP 304 OR |
| STEEL COMP 305 OR |
| STEEL COMP 316 OR |
| STEEL COMP 384 OR |
| STEEL OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | 66 FED STD 1ST MATERIAL RESPONSE OR |
| 66 FED STD 2ND MATERIAL RESPONSE OR |
| 66 FED STD 3RD MATERIAL RESPONSE OR |
| 66 FED STD 4TH MATERIAL RESPONSE OR |
| 66 FED STD 5TH MATERIAL RESPONSE OR |
| ASTM-A493 AISI XM-7 ASSN STD 6TH MATERIAL RESPONSE OVERALL |
| HARDNESS RATING | 80.0 ROCKWELL B MINIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 90000 POUNDS PER SQUARE INCH |
| MINIMUM YIELD STRENGTH | 30000 POUNDS PER SQUARE INCH |
| HEAD STYLE | BUTTON |
| HEAD DIAMETER | 0.250 INCHES MINIMUM AND |
| 0.262 INCHES MAXIMUM |
| HEAD HEIGHT | 0.063 INCHES MINIMUM AND |
| 0.073 INCHES MAXIMUM |
| INTERNAL DRIVE STYLE | HEXAGON |
| WIDTH ACROSS FLATS | 0.0781 INCHES MINIMUM AND |
| 0.0791 INCHES MAXIMUM |
| THE MANUFACTURERS DATA | |
| MANUFACTURERS CODE | 66503 |
| DESIGN CONTROL REFERENCE | 1101-520 |