The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-203-8366, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 20 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-01-203-8366 |
| 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 | 0.126 INCHES MINIMUM AND 0.141 INCHES MAXIMUM IN |
| Fastener Length | 3.668 INCHES MINIMUM AND 3.688 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY2,CL2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.402 INCHES MINIMUM AND 0.438 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 41.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.076 INCHES MINIMUM AND 0.086 INCHES MAXIMUM FIRST HOLE IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | CROWNED HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 3.250 INCHES MINIMUM AND 3.266 INCHES MAXIMUM IN |
| Width Between Flats | 0.422 INCHES MINIMUM AND 0.488 INCHES MAXIMUM IN |
| Grip Diameter | 0.2483 INCHES MINIMUM AND 0.2492 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP E4340 OR STEEL COMP 4140 OR STEEL COMP 8740 OR STEEL COMP 4130 OR STEEL COMP 6150 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 3.578 INCHES MINIMUM AND 3.588 INCHES MAXIMUM FIRST HOLE 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 |
|---|---|
| MS27576-4-52 | 5/9 Secondary reference U.S. Government activity |
| MS27576-4-52 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-01-203-8366 is a Bolt,close Tolerance, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-01-203-8366: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.126 INCHES MINIMUM AND 0.141 INCHES MAXIMUM IN; Fastener Length: 3.668 INCHES MINIMUM AND 3.688 INCHES MAXIMUM IN. 20 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.