The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-365-5763, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 17 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-365-5763 |
| Primary Part Number | 73781CS-428 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Sps Technologies, Llc Dba PB Fasteners |
| Status | ACTIVE |
| Washer Outside Diameter | 0.420 INCHES MAXIMUM IN |
| Width Across Flats | 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | AMS 2410 ASSN STD SINGLE TREATMENT RESPONSE OR AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Precious Material | SILVER |
| Hardness Rating | 46.0 ROCKWELL C MAXIMUM |
| Washer Thickness | 0.025 INCHES NOMINAL IN |
| Material Document and Classification | AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5732 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Surface Treatment | SILVER OVERALL |
| Precious Material and Location | ENTIRE SURFACE SILVER |
| Nut Style | CASTELLATED HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | N |
| Part Number | Manufacturer |
|---|---|
| 73781CS-428 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| PHCR-54 PRIMARY | Alcoa Global Fasteners, Inc Dba Simmonds Mecaero Fas Pdts Div Simmonds Mecaero Fas Pdts (USA) |
| HC54709-4 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| 3D0026-4 | 5/2 Secondary reference U.S. Government activity |
NSN 5310-01-365-5763 is a Nut,self-Locking,extended Washer, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-365-5763 has 3 manufacturer part numbers on file: 73781CS-428 (Sps Technologies, Llc Dba PB Fasteners), PHCR-54 (Alcoa Global Fasteners, Inc Dba Simmonds Mecaero Fas Pdts Div Simmonds Mecaero Fas Pdts), HC54709-4 (Howmet Global Fastening Systems Inc).
Key specifications for 73781CS-428: Overall Height: 0.281 INCHES NOMINAL IN; Washer Outside Diameter: 0.420 INCHES MAXIMUM IN; Width Across Flats: 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN; Surface Treatment Document and Classification: AMS 2410 ASSN STD SINGLE TREATMENT RESPONSE OR AMS 2411 ASSN STD SINGLE TREATMENT RESPONSE OVERALL. 17 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.