The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-037-8903, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-037-8903 |
| Primary Part Number | ST3M729-6D31 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Sps Technologies, Llc Dba PB Fasteners |
| Status | ACTIVE |
| Head Height | 0.200 INCHES MINIMUM AND 0.220 INCHES MAXIMUM IN |
| Fastener Length | 2.313 INCHES MINIMUM AND 2.360 INCHES MAXIMUM IN |
| Thread Length | 0.365 INCHES MINIMUM AND 0.432 INCHES MAXIMUM IN |
| Shank Unthreaded Hole Diameter | 0.106 INCHES MINIMUM AND 0.111 INCHES MAXIMUM FIRST HOLE IN |
| Material Document and Classification | 23-112,MCDONNEL DOUGLAS CORP MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | DOUBLE HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.928 INCHES MINIMUM AND 1.948 INCHES MAXIMUM IN |
| Width Between Flats | 0.553 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Grip Diameter | 0.3740 INCHES MINIMUM AND 0.3745 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 2.185 INCHES MINIMUM AND 2.252 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 |
|---|---|
| ST3M729-6D31 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| ST3M729-6D31 PRIMARY | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| ST3M729-6D31 PRIMARY | Hi-Shear Corporation (USA) |
| ST3M729-6D31 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| MB145-6D31 PRIMARY | Hi-Shear Corporation (USA) |
| ST3M729-6D31 PRIMARY | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| MB145-6D31 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| ST3M729-6D31 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST3M729-6D31 PRIMARY | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M729-6D31 PRIMARY | Heartland Precision Fasteners Inc (USA) |
| Reference | Meaning |
|---|---|
| ST3M729-6D31 | 5/9 Secondary reference U.S. Government activity |
| ST3M729-6D31 | 5/9 Secondary reference U.S. Government activity |
| ST3M729-6D31 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| ST3M729-6D31 | 5/9 Secondary reference U.S. Government activity |
NSN 5306-01-037-8903 is a Bolt,close Tolerance, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-037-8903 has 10 manufacturer part numbers on file: ST3M729-6D31 (Sps Technologies, Llc Dba PB Fasteners), ST3M729-6D31 (Valley-Todeco, Inc. Dba Arconic Fastening Systems), ST3M729-6D31 (Hi-Shear Corporation), ST3M729-6D31 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), MB145-6D31 (Hi-Shear Corporation) and 5 more.
Key specifications for ST3M729-6D31: Head Height: 0.200 INCHES MINIMUM AND 0.220 INCHES MAXIMUM IN; Fastener Length: 2.313 INCHES MINIMUM AND 2.360 INCHES MAXIMUM IN; Thread Length: 0.365 INCHES MINIMUM AND 0.432 INCHES MAXIMUM IN; Shank Unthreaded Hole Diameter: 0.106 INCHES MINIMUM AND 0.111 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.