bolts › close tolerance bolts
NAS1204-20
Close Tolerance Bolt
Description
Fastener Length: 1-37/64", Thread: 1/4-28, Thread Length: 21/64
Specifications
| Countersink Angle | Between 99.0 degrees and 101.0 degrees |
|---|---|
| Fastener Length | Between 1.551 inches and 1.581 inches |
| Grip Diameter | Between 0.2485 inches and 0.2495 inches |
| Grip Length | Between 1.240 inches and 1.260 inches |
| Hardness Rating | 36.0 rockwell c and 40.0 rockwell c |
| Head Diameter | Between 0.499 inches and 0.507 inches |
| Head Style | Flat countersunk |
| Internal Drive Style | Cross recess type 1 |
| Material | Steel |
| Material Specification | Mil-s-5626 military specification 1st material response or mil-s-5000 military specification 2nd material response or mil-s-8503 military specification 3rd material response or mil-s-6098 military specification 4th material response or mil-s-6049 military specification 5th material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Specification Data | 80205-nas1204 professional/industrial association standard |
| Surface Treatment | Cadmium and chromate |
| Surface Treatment Specification | Cl 3 federal specification all treatment responses type 2 qq-p-416 |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.291 inches and 0.341 inches |
| Thread Qty | 28 |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series | UNF |
| Thread Series Designator | Unf (fine thread) |
| Thread Size | 1/4 |
Cross-reference
No interchangeable or dimensionally similar parts are on record for NAS1204-20. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error