The Bolt,machine, cataloged under National Stock Number 5306-01-398-5031, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 23 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-398-5031 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Surface Finish | 32.0 MICROINCHES FASTENER |
| Extended Washer Thickness | 0.091 INCHES NOMINAL IN |
| Head Height | 0.388 INCHES NOMINAL IN |
| Fastener Length | 1.812 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-416 TY2 CL2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Extended Washer Diameter | 0.639 INCHES MINIMUM AND 0.649 INCHES MAXIMUM IN |
| Thread Length | 0.625 INCHES NOMINAL IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-8503 MIL SPEC 4TH MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Features Provided | FINISHED HEAD |
| Head Style | DOUBLE HEXAGON W/HOLE |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.177 INCHES MINIMUM AND 1.197 INCHES MAXIMUM IN |
| Width Between Flats | 0.437 INCHES NOMINAL IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 8740 OR STEEL COMP 6150 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| 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 |
|---|---|
| MIL-B-8831 | 5/9 Secondary reference U.S. Government activity |
| MS21250-06019 | 5/9 Secondary reference U.S. Government activity |
| MS21250-06019 | 3/2 Design control — primary reference U.S. Government activity |
| NASM8831 | 3/1 Design control — primary reference U.S. Government activity |
NSN 5306-01-398-5031 is a Bolt,machine, classified under FSC 5306, Bolts. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5306-01-469-5429. Verify interchangeability with system specifications before substitution.
Key specifications for 5306-01-398-5031: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Surface Finish: 32.0 MICROINCHES FASTENER; Extended Washer Thickness: 0.091 INCHES NOMINAL IN. 23 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.