The Bolt,machine, cataloged under National Stock Number 5306-00-267-8910, 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 15 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-00-267-8910 |
| Primary Part Number | VS2521-4F10 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Head Height | 0.164 INCHES NOMINAL IN |
| Fastener Length | 0.918 INCHES NOMINAL IN |
| Thread Length | 0.293 INCHES MINIMUM IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Features Provided | FINISHED HEAD |
| Head Style | DOUBLE HEXAGON |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 56878-EWSB22 MANUFACTURERS STANDARD |
| Grip Length | 0.625 INCHES NOMINAL IN |
| Width Between Flats | 0.437 INCHES NOMINAL IN |
| Surface Treatment | CADMIUM OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| 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 |
|---|---|
| AIC220-4A10 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| VS2521-4F10 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| EWSB22-4A10 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| BM55132-4-10A | 5/9 Secondary reference Huck International, Inc |
| VS2521-4F10 | 5/9 Secondary reference U.S. Government activity |
| C081-4-10 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| VS2521F4-10 | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| C081-4-10 | 7/2 Vendor item drawing reference U.S. Government activity |
| AIC516B4-10 | C/1 Advisory reference — outside the item-of-supply concept Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company |
| GB511B4-10 | 7/2 Vendor item drawing reference Northrop Grumman Systems Corporation |
| BM55132-4-10A | 5/9 Secondary reference U.S. Government activity |
NSN 5306-00-267-8910 is a Bolt,machine, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-267-8910 has 3 manufacturer part numbers on file: AIC220-4A10 (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), VS2521-4F10 (Howmet Global Fastening Systems Inc), EWSB22-4A10 (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for VS2521-4F10: Head Height: 0.164 INCHES NOMINAL IN; Fastener Length: 0.918 INCHES NOMINAL IN; Thread Length: 0.293 INCHES MINIMUM IN; Nominal Thread Diameter: 0.250 INCHES IN. 15 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.