The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-309-4338, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 25 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-309-4338 |
| 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 | 0.189 INCHES MINIMUM AND 0.204 INCHES MAXIMUM IN |
| Fastener Length | 2.539 INCHES MINIMUM AND 2.559 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 2 FED SPEC SINGLE TREATMENT RESPONSE FASTENER |
| Thread Length | 0.523 INCHES MINIMUM AND 0.559 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 41.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.106 INCHES MINIMUM AND 0.116 INCHES MAXIMUM FIRST HOLE IN |
| Material Document and Classification | AMS 5643 ASSN STD 1ST MATERIAL RESPONSE OR AMS 5644 ASSN STD 2ND MATERIAL RESPONSE OR QQ-S-763 FED SPEC 3RD MATERIAL RESPONSE LOCKING FEATURE |
| Material Document and Classification | MIL-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5626 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-6758 MIL SPEC 4TH MATERIAL RESPONSE OR MIL-S-8503 MIL SPEC 5TH MATERIAL RESPONSE FASTENER |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | CROWNED HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 2.000 INCHES MINIMUM AND 2.016 INCHES MAXIMUM IN |
| Width Between Flats | 0.553 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Grip Diameter | 0.3733 INCHES MINIMUM AND 0.3742 INCHES MAXIMUM IN |
| Locking Feature | RETAINER GRIP |
| Surface Treatment | CADMIUM AND CHROMATE FASTENER |
| Minimum Tensile Strength | 95000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL COMP 630 OR STEEL COMP 631 OR STEEL COMP 440C LOCKING FEATURE |
| Material | STEEL COMP E4340 OR STEEL COMP 4140 OR STEEL COMP 8740 OR STEEL COMP 4130 OR STEEL COMP 6150 FASTENER |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 2.424 INCHES MINIMUM AND 2.454 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 |
|---|---|
| NASM27576-6-32 | 3/2 Design control — primary reference U.S. Government activity |
| MS27576-6-32 | 5/9 Secondary reference U.S. Government activity |
| MS27576-6-32 | 3/9 Design control — primary reference U.S. Government activity |
NSN 5306-01-309-4338 is a Bolt,close Tolerance, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-01-309-4338: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.189 INCHES MINIMUM AND 0.204 INCHES MAXIMUM IN; Fastener Length: 2.539 INCHES MINIMUM AND 2.559 INCHES MAXIMUM IN. 25 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.