bolts › close tolerance bolts
NAS1221R4E4
Close Tolerance Bolt
Description
Fastener Length: 11/16", Thread: 1/4-28, Thread Length: 27/64
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Fastener Length | 0.661 inches minimum and 0.691 inches maximum |
| Head Diameter | 0.461 inches minimum and 0.507 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Torque-set ribbed |
| Length | 11/16 |
| Material | Iron |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Part Name Assigned By Controlling Agency | Navy special project |
| Screw Material | Iron alloy 660 |
| Screw Material Specification | Ama5731 assn std single material response or ama5732 assn std single material response or ams5737 assn std single material response |
| Screw Surface Treatment | Passivate |
| Screw Surface Treatment Specification | Qq-p-35 fed spec single treatment response |
| Specification Data | 80205-nas1221 professional/industrial association standard |
| Thread Class | 3a |
| Thread Diameter | 0.250 |
| Thread Direction | Right-hand |
| Thread Length | 0.425 |
| 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.
- NAS1221R4E3
- NAS1221R4E4
- NAS1221R4E5
- NAS1221R4E6
- NAS1221R4E23
Cross-reference
No interchangeable or dimensionally similar parts are on record for NAS1221R4E4. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error