The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-079-1366, 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 14 specifications, cited from the U.S. Government catalog. The record lists 17 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-079-1366 |
| Primary Part Number | ST3M453-4-21 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Head Height | 0.154 INCHES MINIMUM AND 0.174 INCHES MAXIMUM IN |
| Fastener Length | 1.693 INCHES MINIMUM AND 1.740 INCHES MAXIMUM IN |
| Thread Length | 0.371 INCHES MINIMUM AND 0.438 INCHES MAXIMUM IN |
| Material Document and Classification | 23-112,FSCM 76301 MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | DOUBLE HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.302 INCHES MINIMUM AND 1.322 INCHES MAXIMUM IN |
| Width Between Flats | 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL CORROSION RESISTING 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 |
|---|---|
| BM17019-4-21 | Huck International, Inc (USA) |
| HP5453-4-21 | Heartland Precision Fasteners Inc (USA) |
| GS1016-4-21 | B & B Specialties Inc Dba Gs Aerospace Div Gs Aerospace (USA) |
| ST3M453-4-21 PRIMARY | The Boeing Company Div Defense (USA) |
| VAL23029-4-21 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| ST3M453-4-21 | Houston Precision Fasteners I Lp (USA) |
| FIT7047-4-21 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| 11825-4-21 | Reid Products Inc. Dba Reid Products Inc (USA) |
| VS3204-4-21 | Howmet Global Fastening Systems Inc (USA) |
| PBF1253-4-21 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| MB61-4-21 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| S11-1060-4-21 | Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries (USA) |
| ST3M453-4-21 | M.s. Aerospace Inc. Dba Ms Aerospace Inc (USA) |
| AIC753-4-21 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| MB61-4-21 | Hi-Shear Corporation (USA) |
| SLB252-4-21 | Space-Lok, Inc. Dba Space-Lok Inc Div Space-Lok (USA) |
| WC453-4-21 | West Coast Aerospace, Inc. (USA) |
| Reference | Meaning |
|---|---|
| VS3204-4-21 | 5/9 Secondary reference U.S. Government activity |
| 109453-4-21 | 5/2 Secondary reference U.S. Government activity |
| BM17019-4-21 | 5/9 Secondary reference U.S. Government activity |
| S353-4-21 | 5/9 Secondary reference U.S. Government activity |
| 109453-4-21 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
NSN 5306-01-079-1366 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-079-1366 has 17 manufacturer part numbers on file: BM17019-4-21 (Huck International, Inc), HP5453-4-21 (Heartland Precision Fasteners Inc), GS1016-4-21 (B & B Specialties Inc Dba Gs Aerospace Div Gs Aerospace), ST3M453-4-21 (The Boeing Company Div Defense), VAL23029-4-21 (Valley-Todeco, Inc. Dba Arconic Fastening Systems) and 12 more.
Key specifications for ST3M453-4-21: Head Height: 0.154 INCHES MINIMUM AND 0.174 INCHES MAXIMUM IN; Fastener Length: 1.693 INCHES MINIMUM AND 1.740 INCHES MAXIMUM IN; Thread Length: 0.371 INCHES MINIMUM AND 0.438 INCHES MAXIMUM IN; Material Document and Classification: 23-112,FSCM 76301 MFR REF SINGLE MATERIAL RESPONSE OVERALL. 14 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.