bolts › close tolerance bolts
NAS1581K4T6
Bolt
Description
Fastener Length: 25/32", Thread: 1/4-28, Thread Length: 27/64"
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Fastener Length | 0.763 inches minimum and 0.793 inches maximum |
| Grip Diameter | 0.2490 inches minimum and 0.2495 inches maximum |
| Grip Length | 0.365 inches minimum and 0.385 inches maximum |
| Head Diameter | 0.3504 inches minimum and 0.3988 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Offset cruciform (torque set) |
| Length | 25/32 |
| Material | Titanium |
| Material Specification | Nas 621 assn std single material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Specification Data | 80205-nas1581 professional/industrial association standard |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.378 inches minimum and 0.428 inches maximum |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNJF |
| Thread Size | 1/4 |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
Cross-reference
Similar parts
Parts with matching key dimensions — often from a different standards family. Candidates for comparison only; verify the full specification before substituting.
- NAS1581A4H6 NAS 1/4-28 · 25/32 in · Flat countersunk · Steel
- NAS1581A4T6 NAS 1/4-28 · 25/32 in · Flat countersunk · Steel
- NAS1581F4H6 NAS 1/4-28 · 25/32 in · Flat countersunk · Steel
- NAS1581F4R6 NAS 1/4-28 · 25/32 in · Flat countersunk · Steel
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Catalog data updated 2026-07-05. Report a data error