The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-338-0949, 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 15 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-338-0949 |
| Primary Part Number | 73783CM-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 | 0.386 INCHES MINIMUM IN |
| Width Across Flats | 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE NUT |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 450.0 FAHRENHEIT MAXIMUM DEGF |
| Washer Thickness | 0.020 INCHES NOMINAL IN |
| Material Document and Classification | AMS 5732 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 | PASSIVATE NUT |
| Nut Style | SLOTTED 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 | X |
| Part Number | Manufacturer |
|---|---|
| 73783CM-428 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| 03A187-4L | Northrop Grumman Systems Corp Dba Northrop Grumman Computing Systems (USA) |
| 03A187-4L | Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems (USA) |
| BH187-4 | Bristol Industries, Llc (USA) |
| Reference | Meaning |
|---|---|
| SMTE9925-4 | 5/9 Secondary reference Harvard Industries Inc |
NSN 5310-01-338-0949 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 5310-01-338-0949 has 4 manufacturer part numbers on file: 73783CM-428 (Sps Technologies, Llc Dba PB Fasteners), 03A187-4L (Northrop Grumman Systems Corp Dba Northrop Grumman Computing Systems), 03A187-4L (Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems), BH187-4 (Bristol Industries, Llc).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-437-0578. Verify interchangeability with system specifications before substitution.
Key specifications for 73783CM-428: Overall Height: 0.188 INCHES NOMINAL IN; Washer Outside Diameter: 0.386 INCHES MINIMUM IN; Width Across Flats: 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE NUT. 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.