The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-256-6881, 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 19 specifications, cited from the U.S. Government catalog. The record lists 9 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-256-6881 |
| Primary Part Number | ST3M731-3-5 |
| 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 |
| Surface Finish | 16.0 MICROINCHES THREADS |
| Head Height | 0.110 INCHES MINIMUM AND 0.125 INCHES MAXIMUM IN |
| Fastener Length | 0.635 INCHES MINIMUM AND 0.665 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | MIL-C-83488,TYPE 2 CLASS 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.313 INCHES MINIMUM AND 0.363 INCHES MAXIMUM IN |
| Material Document and Classification | AMS4967 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.302 INCHES MINIMUM AND 0.322 INCHES MAXIMUM IN |
| Width Between Flats | 0.367 INCHES MINIMUM AND 0.376 INCHES MAXIMUM IN |
| Grip Diameter | 0.1885 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN |
| Surface Treatment | ALUMINUM OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | TITANIUM ALLOY UNS R56400 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 |
| Part Number | Manufacturer |
|---|---|
| ST3M731-3-5 | Howmet Global Fastening Systems Inc (USA) |
| ST3M731-3-5 PRIMARY | The Boeing Company Div Defense (USA) |
| ST3M731-3-5 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| ST3M731-3-5 | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| ST3M731-3-5 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| PBF1264-3-5 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| MB251-3-5 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| ST3M731-3-5 | Hi-Shear Corporation (USA) |
| MB251-3-5 | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| ST3M7 | 5/9 Secondary reference Sps Technologies Inc |
| ST3M731-3-5 | 5/9 Secondary reference U.S. Government activity |
| VS3207-3-5 | 5/9 Secondary reference U.S. Government activity |
| SC2663-3-5 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| VS3207-3-5 | C/1 Advisory reference — outside the item-of-supply concept Howmet Global Fastening Systems Inc |
| 801651-3-5 | 5/9 Secondary reference Sps Technologies Inc |
NSN 5306-01-256-6881 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-256-6881 has 9 manufacturer part numbers on file: ST3M731-3-5 (Howmet Global Fastening Systems Inc), ST3M731-3-5 (The Boeing Company Div Defense), ST3M731-3-5 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), ST3M731-3-5 (Sps Technologies Ltd, Tj Brooks Division), ST3M731-3-5 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc) and 4 more.
Key specifications for ST3M731-3-5: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Surface Finish: 16.0 MICROINCHES THREADS; Head Height: 0.110 INCHES MINIMUM AND 0.125 INCHES MAXIMUM IN. 19 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.