The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-151-0331, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 26 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-00-151-0331 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.140 INCHES MINIMUM AND 0.172 INCHES MAXIMUM IN |
| Fastener Length | 2.156 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.468 INCHES MINIMUM IN |
| Hardness Rating | 26.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.076 INCHES NOMINAL FIRST HOLE IN |
| Hole Configuration Style | HEXAGON FLATS |
| Material Document and Classification | MIL-S-6049 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-6050 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6098 MIL SPEC 3RD MATERIAL RESPONSE OR AMS 6300 ASSN STD 4TH MATERIAL RESPONSE OR MIL-S-6758 MIL SPEC 5TH MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 6TH MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.688 INCHES NOMINAL IN |
| Width Between Flats | 0.428 INCHES MINIMUM AND 0.440 INCHES MAXIMUM IN |
| Grip Diameter | 0.2487 INCHES MINIMUM AND 0.2492 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 125000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 8740 OR STEEL COMP 8630 OR STEEL COMP 8735 OR STEEL COMP 4037 OR STEEL COMP 4130 OR STEEL COMP 4140 OVERALL |
| Hole Quantity | 1 |
| Thread Series Designator | UNF |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 2.000 INCHES NOMINAL FIRST HOLE IN |
| Hole Type | DRILLED |
| Hole Diameter | 0.046 INCHES NOMINAL 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 |
|---|---|
| AN174H21 | 2/2 Government specification standardization U.S. Government activity |
| B6812 | 4/1 Identification reference U.S. Government activity |
NSN 5306-00-151-0331 is a Bolt,close Tolerance, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-00-151-0331: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.140 INCHES MINIMUM AND 0.172 INCHES MAXIMUM IN; Fastener Length: 2.156 INCHES NOMINAL IN. 26 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.