The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-680-8652, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 4 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5310-01-680-8652 |
| Primary Part Number | KFN668-8 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Washer Outside Diameter | 0.777 INCHES MINIMUM IN |
| Width Across Flats | 0.553 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Washer Thickness | 0.132 INCHES MINIMUM AND 0.142 INCHES MAXIMUM IN |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.50 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Surface Treatment | PASSIVATE OVERALL |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| 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 |
|---|---|
| KFN668-8 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| KFN668-8 PRIMARY | Huck International, Inc (USA) |
| BH00620M8 PRIMARY | Bristol Industries, Llc (USA) |
| KFN668-8 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| LE114-0031-0008 | 7/2 Vendor item drawing reference The Boeing Company Div Legacy Am&m |
| KFN668-8 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-680-8652 is a Nut,self-Locking,extended Washer, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-680-8652 has 4 manufacturer part numbers on file: KFN668-8 (Howmet Global Fastening Systems Inc), KFN668-8 (Huck International, Inc), BH00620M8 (Bristol Industries, Llc), KFN668-8 (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for KFN668-8: Overall Height: 0.615 INCHES MAXIMUM IN; Washer Outside Diameter: 0.777 INCHES MINIMUM IN; Width Across Flats: 0.553 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF). 12 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.