The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-448-0074, 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 15 specifications, cited from the U.S. Government catalog. The record lists 7 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 7 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-448-0074 |
| Primary Part Number | ST2785-10 |
| 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 | 0.410 INCHES MINIMUM IN |
| Width Across Flats | 0.312 INCHES NOMINAL IN |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Hardness Rating | 24.0 ROCKWELL C MINIMUM |
| Criticality Code Justification | FEAT |
| Washer Thickness | 0.045 INCHES MINIMUM AND 0.060 INCHES MAXIMUM IN |
| Material Document and Classification | 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 |
| Countersink Angle | 85.0 DEGREES MINIMUM AND 95.0 DEGREES MAXIMUM NUT |
| Nut Style | DOUBLE 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 | Y |
| Part Number | Manufacturer |
|---|---|
| ST2783-10 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| ST2785-10 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| ST2785-10 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| ST2780-10 | Howmet Global Fastening Systems Inc (USA) |
| ST2785-10 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST2780-10 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| ST2782-10 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| LH13587-4 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| VN4761BB048 | 5/9 Secondary reference U.S. Government activity |
| ST2785-10 | 5/2 Secondary reference U.S. Government activity |
| 92617-428 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| ST2781-10 | 5/9 Secondary reference Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| H53777-4 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| 5310PL0754410 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
NSN 5310-01-448-0074 is a Nut,self-Locking,extended Washer, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-448-0074 has 7 manufacturer part numbers on file: ST2783-10 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney), ST2785-10 (Sps Technologies, Llc Dba PB Fasteners), ST2785-10 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney), ST2780-10 (Howmet Global Fastening Systems Inc), ST2785-10 (Howmet Global Fastening Systems Inc) and 2 more.
1 possible match (shared part number, not a government interchangeability claim): 5310-01-702-3779. Verify interchangeability with system specifications before substitution.
Key specifications for ST2785-10: Overall Height: 0.308 INCHES MINIMUM AND 0.328 INCHES MAXIMUM IN; Washer Outside Diameter: 0.410 INCHES MINIMUM IN; Width Across Flats: 0.312 INCHES NOMINAL IN; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF). 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.