THREAD SERIES DESIGNATOR | UNF |
NOMINAL THREAD DIAMETER | 0.138 INCHES |
THREAD QUANTITY PER INCH | 40 |
THREAD CLASS | 2A |
THREAD DIRECTION | RIGHT-HAND |
THREAD LENGTH | 0.419 INCHES MINIMUM AND |
| 0.500 INCHES MAXIMUM |
FASTENER LENGTH | 0.469 INCHES MINIMUM AND |
| 0.500 INCHES MAXIMUM |
MATERIAL | STEEL COMP 1050 OR |
| STEEL COMP 1566 PRIMARY WASHER |
MATERIAL DOCUMENT AND CLASSIFICATION | SAE ASSN STD 2ND MATERIAL RESPONSE PRIMARY WASHER |
| SAE ASSN STD 1ST MATERIAL RESPONSE FASTENER |
SURFACE TREATMENT | CADMIUM OR |
| ZINC PRIMARY WASHER |
| CADMIUM OR |
| ZINC FASTENER |
HARDNESS RATING | 40.0 ROCKWELL C MINIMUM AND |
| 50.0 ROCKWELL C MAXIMUM PRIMARY WASHER |
HEAD STYLE | DISHED HEXAGON |
HEAD HEIGHT | 0.067 INCHES MINIMUM AND |
| 0.080 INCHES MAXIMUM |
WIDTH BETWEEN FLATS | 0.245 INCHES MINIMUM AND |
| 0.250 INCHES MAXIMUM |
INTERNAL DRIVE STYLE | W/O INTERNAL DRIVE |
WASHER QUANTITY | 1 |
PRIMARY WASHER STYLE | FLAT EXTERNAL TEETH |
PRIMARY WASHER OUTSIDE DIAMETER | 0.270 INCHES MINIMUM AND |
| 0.280 INCHES MAXIMUM |
PRIMARY WASHER MATERIAL THICKNESS | 0.016 INCHES NOMINAL |
SPEC/STD CONTROLLING DATA | |
MANUFACTURERS CODE | 21450 |
DEFINITIVE GOVERNMENT SPEC/STD REFERENCE | 425544 |