screws › close tolerance screws
NAS1581C3R4
Close Tolerance Screw
Description
Flush Reduced Head Bolt
Specifications
| Countersink Angle | Between 99.0 degrees and 101.0 degrees |
|---|---|
| Country of Origin | USA |
| Fastener Length | Between 0.598 inches and 0.628 inches |
| Grip Diameter | Between 0.1885 inches and 0.1895 inches |
| Grip Length | Between 0.240 inches and 0.260 inches |
| Head Diameter | Between 0.258 inches and 0.305 inches |
| Head Style | Flat countersunk |
| Internal Drive Style | Offset cruciform (torque set) |
| Length | 5/8 |
| Material | Iron |
| Material Specification | Ams5731 assn standard single material response or ams5732 assn standard single material response or ams5737 assn standard single material response |
| Min. Tensile Strength (psi) | 160000 pounds per square inch |
| NIIN | 01-193-7609 |
| NSN | 5305-01-193-7609 |
| 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 federal specification single treatment response |
| Thread Class | 3a |
| Thread Diameter | 0.190 |
| Thread Direction | Right-hand |
| Thread Length | Between 0.338 inches and 0.388 inches |
| Thread Qty | 32 |
| Thread Qty Per Inch (tpi) | 32 |
| Thread Series | UNJF |
| Thread Series Designator | Unjf (fine thread with external controlled root radius) |
| Thread Size | 10 |
| Weight | 0.0045 lb |
Other sizes
Parts that share this base number, ordered by size. Always verify the full specification before substituting.
- NAS1581C3R2
- NAS1581C3R2P
- NAS1581C3R3
- NAS1581C3R4
- NAS1581C3R4P
- NAS1581C3R6P
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.
- NAS1581F3R4 NAS #10-32 · 5/8 in · Flat countersunk · Steel
- NAS1581F3T4 NAS #10-32 · 5/8 in · Flat countersunk · Steel
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Catalog data updated 2026-07-05. Report a data error