screws › machine screws
NAS1221-4-7
Machine Screw
Description
Machine Screw
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Fastener Length | 0.849 inches minimum and 0.879 inches maximum |
| Hardness Rating | 36.0 rockwell c minimum and 40.0 rockwell c maximum |
| Head Diameter | 0.461 inches minimum and 0.507 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | High-torque |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Screw Material | Steel comp 4140 or steel comp e4340 or steel comp 8740 |
| Screw Material Specification | Mil-s-5626 mil spec 1st material response or mil-s-5000 mil spec 2nd material response or mil-s-6049 mil spec 3rd material response |
| Screw Surface Treatment | Cadmium |
| Screw Surface Treatment Specification | Qq-p-416,ty 1,cl 3 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 | 0.401 inches minimum and 0.451 inches maximum |
| Thread Qty Per Inch (tpi) | 28 |
| Thread Series Designator | UNJF |
Cross-reference
No interchangeable or dimensionally similar parts are on record for NAS1221-4-7. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error