The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-256-4461, 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 16 specifications, cited from the U.S. Government catalog. The record lists 10 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-01-256-4461 |
| Primary Part Number | ST3M729-5D18 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Head Height | 0.177 INCHES MINIMUM AND 0.197 INCHES MAXIMUM IN |
| Fastener Length | 1.484 INCHES MINIMUM AND 1.531 INCHES MAXIMUM IN |
| Thread Length | 0.349 INCHES MINIMUM AND 0.416 INCHES MAXIMUM IN |
| Shank Unthreaded Hole Diameter | 0.076 INCHES MINIMUM AND 0.081 INCHES MAXIMUM FIRST HOLE IN |
| Nominal Thread Diameter | 0.312 INCHES IN |
| Head Style | DOUBLE HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.115 INCHES MINIMUM AND 1.135 INCHES MAXIMUM IN |
| Width Between Flats | 0.492 INCHES MINIMUM AND 0.502 INCHES MAXIMUM IN |
| Grip Diameter | 0.3115 INCHES MINIMUM AND 0.3120 INCHES MAXIMUM IN |
| Minimum Tensile Strength | 125000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 1.356 INCHES MINIMUM AND 1.423 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 |
|---|---|
| ST3M729-5D18 | Heartland Precision Fasteners Inc (USA) |
| ST3M729-5D18 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| ST3M729-5D18 PRIMARY | The Boeing Company Div Defense (USA) |
| ST3M729-5D18 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| MB145-5D18 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| MB145-5D18 | Hi-Shear Corporation (USA) |
| ST3M729-5D18 | Howmet Global Fastening Systems Inc (USA) |
| ST3M729-5D18 | Huck International, Inc (USA) |
| ST3M729-5D18 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| ST3M729-5D18 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| Reference | Meaning |
|---|---|
| ST3M729-5D18 | 5/9 Secondary reference U.S. Government activity |
| ST3M729-5D18 | 5/2 Secondary reference U.S. Government activity |
NSN 5306-01-256-4461 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-256-4461 has 10 manufacturer part numbers on file: ST3M729-5D18 (Heartland Precision Fasteners Inc), ST3M729-5D18 (Valley-Todeco, Inc. Dba Arconic Fastening Systems), ST3M729-5D18 (The Boeing Company Div Defense), ST3M729-5D18 (Sps Technologies, Llc Dba PB Fasteners), MB145-5D18 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc) and 5 more.
Key specifications for ST3M729-5D18: Head Height: 0.177 INCHES MINIMUM AND 0.197 INCHES MAXIMUM IN; Fastener Length: 1.484 INCHES MINIMUM AND 1.531 INCHES MAXIMUM IN; Thread Length: 0.349 INCHES MINIMUM AND 0.416 INCHES MAXIMUM IN; Shank Unthreaded Hole Diameter: 0.076 INCHES MINIMUM AND 0.081 INCHES MAXIMUM FIRST HOLE IN. 16 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.