The Bolt,machine, cataloged under National Stock Number 5306-01-137-1785, 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 7 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through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-01-137-1785 |
| Primary Part Number | ST3M731-4D16 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| 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 | 1.410 INCHES MINIMUM AND 1.410 INCHES MINIMUM AND 1.440 INCHES MAXIMUM1.440 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | MIL-C-83488 TYPE 2 CLASS 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALLMIL-C-83488 TYPE 2 CLASS 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.400 INCHES MINIMUM AND 0.400 INCHES MINIMUM AND 0.450 INCHES MAXIMUM0.450 INCHES MAXIMUM IN |
| Shank Unthreaded Hole Diameter | 0.076 INCHES MINIMUM AND 0.076 INCHES MINIMUM AND 0.086 INCHES MAXIMUM FIRST HOLE0.086 INCHES MAXIMUM FIRST HOLE 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 |
| Grip Length | 0.990 INCHES MINIMUM AND 0.990 INCHES MINIMUM AND 1.010 INCHES MAXIMUM1.010 INCHES MAXIMUM IN |
| 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) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 1.219 INCHES MINIMUM AND 1.219 INCHES MINIMUM AND 1.269 INCHES MAXIMUM FIRST HOLE1.269 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 |
|---|---|
| PBF1264-4D16 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| MB251-4D16 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| ST3M731-4D16 PRIMARY | The Boeing Company Div Defense (USA) |
| MB251-4D16 | Hi-Shear Corporation (USA) |
| 111364-4D16 | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| SC2663-4-16D | Howmet Global Fastening Systems Inc (USA) |
| ST3M731-4D16 | Howmet Global Fastening Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| ST3M731-4D16 | 5/2 Secondary reference U.S. Government activity |
| 801651-4D16 | 5/9 Secondary reference Sps Technologies Inc |
| VS3207-4-16D | 5/9 Secondary reference U.S. Government activity |
| 10115962 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| VS3207-4-16D | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| ST3M731-4D16 | 5/9 Secondary reference Sps Technologies Inc |
NSN 5306-01-137-1785 is a Bolt,machine, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-137-1785 has 7 manufacturer part numbers on file: PBF1264-4D16 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), MB251-4D16 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), ST3M731-4D16 (The Boeing Company Div Defense), MB251-4D16 (Hi-Shear Corporation), 111364-4D16 (Sps Technologies Ltd, Tj Brooks Division) and 2 more.
Key specifications for ST3M731-4D16: 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. 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.