The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-071-9529, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 21 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-071-9529 |
| Primary Part Number | ST3M735-4-37 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| 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 | 2.731 INCHES MINIMUM AND 2.751 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.283 INCHES MINIMUM AND 0.334 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 | DISHED HEXAGON |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 76301-ST3-735 MANUFACTURERS STANDARD |
| Grip Length | 2.312 INCHES MINIMUM AND 2.328 INCHES MAXIMUM IN |
| Width Between Flats | 0.430 INCHES MINIMUM AND 0.439 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 | 2.631 INCHES MINIMUM AND 2.661 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 |
| Part Number | Manufacturer |
|---|---|
| ST3M735-4-37 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| ST3M735-4-37 | 5/2 Secondary reference U.S. Government activity |
| 121673-4-37 | 5/2 Secondary reference U.S. Government activity |
NSN 5306-01-071-9529 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-071-9529 has 1 manufacturer part number on file: ST3M735-4-37 (The Boeing Company Div Defense).
Key specifications for ST3M735-4-37: 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: 2.731 INCHES MINIMUM AND 2.751 INCHES MAXIMUM IN. 21 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.