screws › close tolerance screws
NAS1581F4T4
Close Tolerance Screw
Description
Flush Reduced Head Bolt
Specifications
| Countersink Angle | 100.0 degrees |
|---|---|
| Country of Origin | USA |
| Fastener Length | 0.653 |
| Grip Diameter | Between 0.248 inches and 0.249 inches |
| Grip Length | Between 0.240 inches and 0.260 inches |
| Hardness Rating | 36.0 rockwell c and 40.0 rockwell c |
| Head Diameter | Between 0.350 inches and 0.399 inches |
| Head Style | Flat countersunk |
| Internal Drive Style | Offset cruciform (torque set) |
| Length | 5/8 |
| Material | Steel |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| NIIN | 01-417-4446 |
| NSN | 5305-01-417-4446 |
| Surface Finish | 32.0 microinches grip, 32.0 microinches threads |
| Surface Treatment | Cadmium or chromate |
| Surface Treatment Specification | Cl2 federal specification single treatment response ty2 qq-p-416 |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.403 |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNJF |
| Thread Series Designator | Unjf (fine thread with external controlled root radius) |
| Thread Size | 1/4 |
| Weight | 0.01 lb |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
No interchangeable or dimensionally similar parts are on record for NAS1581F4T4. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error