The Bolt,machine, cataloged under National Stock Number 5306-01-138-7722, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Hi-Shear Corporation. Government technical data includes 18 specifications, cited from the U.S. Government catalog. The record lists 7 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-138-7722 |
| Primary Part Number | ST3M731-4-2 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Surface Finish | 16.0 MICROINCHES THREADS16.0 MICROINCHES THREADS |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Surface Finish | 63.0 MICROINCHES GRIP63.0 MICROINCHES GRIP |
| Head Height | 0.125 INCHES MINIMUM AND 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM0.140 INCHES MAXIMUM IN |
| Fastener Length | 0.535 INCHES MINIMUM AND 0.535 INCHES MINIMUM AND 0.565 INCHES MAXIMUM0.565 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | MIL-C-83488,TY 2,CL 3 MIL SPEC ALL TREATMENT RESPONSES OVERALLMIL-C-83488,TY 2,CL 3 MIL SPEC ALL TREATMENT RESPONSES OVERALL |
| Thread Length | 0.400 INCHES MINIMUM AND 0.400 INCHES MINIMUM AND 0.450 INCHES MAXIMUM0.450 INCHES MAXIMUM IN |
| Material Document and Classification | AMS4967 ASSN STD SINGLE MATERIAL RESPONSE OVERALLAMS4967 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES0.250 INCHES IN |
| Features Provided | FINISHED HEADFINISHED HEAD |
| Head Style | HEXAGONHEXAGON |
| Thread Direction | RIGHT-HANDRIGHT-HAND |
| Width Between Flats | 0.430 INCHES MINIMUM AND 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM0.439 INCHES MAXIMUM IN |
| Surface Treatment | ALUMINUM AND ALUMINUM AND CHROMATE OVERALLCHROMATE OVERALL |
| Thread Class | 3A3A |
| Thread Quantity Per Inch | 2828 |
| Material | TITANIUM ALLOY UNS R56400 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF)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 |
|---|---|
| ST3M731-4-2 PRIMARY | Hi-Shear Corporation (USA) |
| 111364-4-2 | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| ST3M731-4-2 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST3M731-4-2 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| MB251-4-2 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| ST3M731-4-2 PRIMARY | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| MB251-4-2 | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| SC2663-4-2 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| VS3207-4-2 | 5/9 Secondary reference U.S. Government activity |
| VS3207-4-2 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| ST3M731-4-2 | 5/9 Secondary reference The Boeing Company Div Defense |
| 801651-4-2 | 5/9 Secondary reference Sps Technologies Inc |
| PBF1264-4-2 | 5/9 Secondary reference Sps Technologies Llc Dba PB Fasteners Div PB Fasteners |
| 10115964 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| ST3M731-4-2 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-01-138-7722 is a Bolt,machine, manufactured by Hi-Shear Corporation, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-138-7722 has 7 manufacturer part numbers on file: ST3M731-4-2 (Hi-Shear Corporation), 111364-4-2 (Sps Technologies Ltd, Tj Brooks Division), ST3M731-4-2 (Howmet Global Fastening Systems Inc), ST3M731-4-2 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), MB251-4-2 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc) and 2 more.
Key specifications for ST3M731-4-2: Surface Finish: 16.0 MICROINCHES THREADS16.0 MICROINCHES THREADS; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD63.0 MICROINCHES BEARING SURFACE OF HEAD; Surface Finish: 63.0 MICROINCHES GRIP63.0 MICROINCHES GRIP; Head Height: 0.125 INCHES MINIMUM AND 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM0.140 INCHES MAXIMUM IN. 18 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.