| THREAD SERIES DESIGNATOR | UNF |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28 |
| THREAD CLASS | 1A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.415 INCHES MINIMUM AND |
| 0.455 INCHES MAXIMUM |
| FASTENER LENGTH | 1.020 INCHES MINIMUM AND |
| 1.040 INCHES MAXIMUM |
| MATERIAL | STEEL COMP 601 OVERALL |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS6304 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | NICKEL OVERALL |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS 2424 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| HARDNESS RATING | 42.0 ROCKWELL C MINIMUM AND |
| 46.0 ROCKWELL C MAXIMUM OVERALL |
| MINIMUM TENSILE STRENGTH | 195000 POUNDS PER SQUARE INCH |
| HEAD STYLE | DOUBLE HEXAGON W/HOLE |
| HEAD HEIGHT | 0.250 INCHES MINIMUM AND |
| 0.270 INCHES MAXIMUM |
| WIDTH BETWEEN FLATS | 0.243 INCHES MINIMUM AND |
| 0.251 INCHES MAXIMUM |
| EXTENDED WASHER DIAMETER | 0.365 INCHES MINIMUM AND |
| 0.385 INCHES MAXIMUM |
| EXTENDED WASHER THICKNESS | 0.040 INCHES MINIMUM AND |
| 0.050 INCHES MAXIMUM |
| SHOULDER SHAPE | ROUND FIRST SHOULDER |
| SHOULDER DIAMETER | 0.2502 INCHES MINIMUM AND |
| 0.2504 INCHES MAXIMUM FIRST SHOULDER |
| SHOULDER LENGTH | 0.490 INCHES MINIMUM AND |
| 0.510 INCHES MAXIMUM FIRST SHOULDER |
| THE MANUFACTURERS DATA | |
| MANUFACTURERS CODE | 99207 |
| DESIGN CONTROL REFERENCE | 3008T57P01 |