The Bolt,square Neck, cataloged under National Stock Number 5306-00-021-8187, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-021-8187 |
| Item Name | Bolt,square Neck |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Neck Length | 0.491 INCHES MINIMUM AND 0.541 INCHES MAXIMUM IN |
| Fastener Length | 2.375 INCHES MINIMUM AND 2.625 INCHES MAXIMUM IN |
| Thread Length | 1.750 INCHES MINIMUM IN |
| Material Document and Classification | QQ-S-633,CANC FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.750 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Neck Width | 0.750 INCHES MINIMUM AND 0.765 INCHES MAXIMUM IN |
| Minimum Yield Strength | 40000 POUNDS PER SQUARE INCH LBS |
| Countersink Angle | 80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 10 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 1.219 INCHES MINIMUM AND 1.303 INCHES MAXIMUM IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| MS35754-58 | 2/2 Government specification standardization U.S. Government activity |
| 7327653 | 5/1 Secondary reference U S Army Tank Automotive Command Amsta-Im-Mm |
NSN 5306-00-021-8187 is a Bolt,square Neck, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-00-021-8187: Neck Length: 0.491 INCHES MINIMUM AND 0.541 INCHES MAXIMUM IN; Fastener Length: 2.375 INCHES MINIMUM AND 2.625 INCHES MAXIMUM IN; Thread Length: 1.750 INCHES MINIMUM IN; Material Document and Classification: QQ-S-633,CANC FED SPEC SINGLE MATERIAL RESPONSE OVERALL. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.