Close Tolerance Screw
| Federal Supply Class | Screws |
| National Stock Number | 5305-01-658-3431 |
| Item Name Code | 29294 |
| Part Numbers | NAS1790-4-9 |
| Serial Number | 016583431 |
Specifications
| THREAD SERIES DESIGNATOR | UNJF |
| NOMINAL THREAD DIAMETER | 0.250 INCHES |
| THREAD QUANTITY PER INCH | 28.0 |
| THREAD CLASS | 3A |
| THREAD DIRECTION | RIGHT-HAND |
| THREAD LENGTH | 0.425 INCHES NOMINAL |
| FASTENER LENGTH | 0.9875 INCHES NOMINAL |
| MATERIAL | STEEL COMP 4140 OR |
| STEEL COMP 4340 OR | |
| STEEL COMP 8740 OVERALL | |
| MATERIAL DOCUMENT AND CLASSIFICATION | AMS6349 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| SURFACE TREATMENT | CADMIUM AND |
| CHROMATE OVERALL | |
| SURFACE TREATMENT DOCUMENT AND CLASSIFICATION | AMS-QQ-P TYPE II, CLASS 2 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| HEAD STYLE | FLAT COUNTERSUNK |
| HEAD DIAMETER | 0.464 INCHES MINIMUM |
| COUNTERSINK ANGLE | 99.0 DEGREES MINIMUM AND |
| 101.0 DEGREES MAXIMUM | |
| INTERNAL DRIVE STYLE | HIGH-TORQUE |
| GRIP LENGTH | 0.5625 INCHES NOMINAL |
| GRIP DIAMETER | 0.2485 INCHES MINIMUM AND |
| 0.2495 INCHES MAXIMUM | |
| DISTANCE FROM HEAD LARGEST BEARING SURFACE TO SHANK HOLE CENTER | 0.8815 INCHES MINIMUM FIRST HOLE |
| SHANK UNTHREADED HOLE DIAMETER | 0.076 INCHES MINIMUM AND |
| 0.086 INCHES MAXIMUM FIRST HOLE | |
| III PART NAME ASSIGNED BY CONTROLLING AGENCY | BOLT 100 DEGREE FLUSH HEAD |
