The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-129-0578, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 5 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through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-01-129-0578 |
| Primary Part Number | SC2663-4-6 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Surface Finish | 16.0 MICROINCHES THREADS |
| Head Height | 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM IN |
| Fastener Length | 0.785 INCHES MINIMUM AND 0.815 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | MIL-C-83488 TYPE 2 CLASS 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.400 INCHES MINIMUM AND 0.450 INCHES MAXIMUM IN |
| Material Document and Classification | NAS 621 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.365 INCHES MINIMUM AND 0.385 INCHES MAXIMUM IN |
| Width Between Flats | 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | ALUMINUM AND CHROMATE OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | TITANIUM ALLOY 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 |
|---|---|
| SC2663-4-6 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| MB251-4-6 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| 111364-4-6 | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| MB251-4-6 PRIMARY | Hi-Shear Corporation (USA) |
| PBF1264-4-6 PRIMARY | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| VS3207-4-6 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| ST3M731-4-6 | 5/9 Secondary reference U.S. Government activity |
| ST3M731-4-6 | 5/9 Secondary reference Sps Technologies Inc |
| VS3207-4-6 | 5/9 Secondary reference U.S. Government activity |
| 111364-4-6 | 3/2 Design control — primary reference U.S. Government activity |
| ST3M731-4-6 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| 801651-4-6 | 5/9 Secondary reference Sps Technologies Inc |
| 10115796 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
NSN 5306-01-129-0578 is a Bolt,close Tolerance, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-129-0578 has 5 manufacturer part numbers on file: SC2663-4-6 (Howmet Global Fastening Systems Inc), MB251-4-6 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), 111364-4-6 (Sps Technologies Ltd, Tj Brooks Division), MB251-4-6 (Hi-Shear Corporation), PBF1264-4-6 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners).
Key specifications for SC2663-4-6: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Surface Finish: 16.0 MICROINCHES THREADS; Head Height: 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM IN. 19 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.