screws › close tolerance screws
NAS1581C4T2
Close Tolerance Screw
Description
Length: 0.528", thread: 1/2-28 shear, flush reduced head bolt, cadmium plated corrosion resistant steel, offset cruciform
Specifications
| Countersink Angle | 99.0 degrees minimum and 101.0 degrees maximum |
|---|---|
| Fastener Length | 0.513 inches minimum and 0.543 inches maximum |
| Grip Diameter | 0.2485 inches minimum and 0.2495 inches maximum |
| Grip Length | 0.115 inches minimum and 0.135 inches maximum |
| Hardness Rating | 24.0 rockwell c minimum and 35.0 rockwell c maximum |
| Head Diameter | 0.3504 inches minimum and 0.3988 inches maximum |
| Head Style | Flat countersunk |
| Internal Drive Style | Offset cruciform (torque set) |
| Length | 17/32 |
| Material | Iron |
| Material Specification | Ams 5731 assn std single material response or ams 5732 assn std single material response or ams 5737 assn std single material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| Special Features | Internal drive ribbed |
| Specification Data | 80205-nas1581 professional/industrial association standard |
| Surface Finish | 32.0 microinches grip, 32.0 microinches threads |
| Surface Treatment | Passivate |
| Surface Treatment Specification | Qq-p-35 fed spec single treatment response |
| 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
No interchangeable or dimensionally similar parts are on record for NAS1581C4T2. Try the cross-reference lookup to search by a different part number.
Catalog data updated 2026-07-05. Report a data error