screws › close tolerance screws
NAS1581F4T9
Close Tolerance Screw
Description
Length: 0.965", thread: 1/4-28 shear, flush reduced head bolt, alloy steel offset cruciform
Specifications
| Countersink Angle | Between 99.0 degrees and 101.0 degrees |
|---|---|
| Fastener Length | Between 0.951 inches and 0.981 inches |
| Grip Diameter | Between 0.2485 inches and 0.2495 inches |
| Grip Length | Between 0.553 inches and 0.573 inches |
| Head Diameter | Between 0.3504 inches and 0.3988 inches |
| Head Style | Flat countersunk |
| Internal Drive Style | Offset cruciform (torque set) |
| Material | Steel |
| Material Specification | Mil-s-5626 military specification 1st material response or mil-s-5000 military specification 2nd material response or mil-s-6040 military specification 3rd material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Specification Data | 80205-nas1581 professional/industrial association standard |
| Surface Treatment | Cadmium and chromate |
| Surface Treatment Specification | Class 2 federal specification all treatment responses type 2 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 |
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 NAS1581F4T9. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error