The Bolt,externally Relieved Body, cataloged under National Stock Number 5306-01-078-3958, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is U S Army Tank Automotive Command Amsta-Im-Mm. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-078-3958 |
| Primary Part Number | 7521739 |
| Item Name | Bolt,externally Relieved Body |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | U S Army Tank Automotive Command Amsta-Im-Mm |
| Status | ACTIVE |
| Head Height | 0.219 INCHES NOMINAL IN |
| Fastener Length | 3.812 INCHES NOMINAL IN |
| Thread Length | 1.250 INCHES NOMINAL IN |
| Material Document and Classification | FF-B-575 GRADE 2 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| First Diameter From Head | 0.375 INCHES NOMINAL IN |
| Distance From Largest Bearing Surface of Head to End of Second Diameter | 2.250 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Second Diameter From Head | 0.330 INCHES MINIMUM AND 0.334 INCHES MAXIMUM IN |
| Width Between Flats | 0.594 INCHES NOMINAL IN |
| Distance From Largest Bearing Surface of Head to End of First Diameter | 0.500 INCHES NOMINAL IN |
| Externally Relieved Body Diameter Quantity | 2 |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 16 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 7521739 PRIMARY | U S Army Tank Automotive Command Amsta-Im-Mm (USA) |
NSN 5306-01-078-3958 is a Bolt,externally Relieved Body, manufactured by U S Army Tank Automotive Command Amsta-Im-Mm, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-078-3958 has 1 manufacturer part number on file: 7521739 (U S Army Tank Automotive Command Amsta-Im-Mm).
Key specifications for 7521739: Head Height: 0.219 INCHES NOMINAL IN; Fastener Length: 3.812 INCHES NOMINAL IN; Thread Length: 1.250 INCHES NOMINAL IN; Material Document and Classification: FF-B-575 GRADE 2 FED SPEC SINGLE MATERIAL RESPONSE OVERALL. 17 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.