The Bolt,internal Wrenching, cataloged under National Stock Number 5306-01-021-4557, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 16 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-021-4557 |
| Item Name | Bolt,internal Wrenching |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Width Across Flats | 0.219 INCHES MINIMUM AND 0.221 INCHES MAXIMUM IN |
| Head Height | 0.226 INCHES NOMINAL IN |
| Fastener Length | 1.375 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.500 INCHES NOMINAL IN |
| Material Document and Classification | MIL-S-6049 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | BEVEL-CONICAL |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | CADMIUM OVERALL |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.430 INCHES MINIMUM AND 0.438 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 |
|---|---|
| NAS144-22 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-01-021-4557 is a Bolt,internal Wrenching, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-01-021-4557: Width Across Flats: 0.219 INCHES MINIMUM AND 0.221 INCHES MAXIMUM IN; Head Height: 0.226 INCHES NOMINAL IN; Fastener Length: 1.375 INCHES NOMINAL IN; Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL. 16 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.