The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-00-899-9173, 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 13 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5310-00-899-9173 |
| Primary Part Number | H42M4 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Lubrication | DRY FILM LUBRICANT |
| Washer Outside Diameter | 0.420 INCHES NOMINAL IN |
| Width Across Flats | 0.281 INCHES NOMINAL IN |
| Thread Series | UNF |
| Temp Rating | 500.0 FAHRENHEIT NOMINAL DEGF |
| Washer Thickness | 0.045 INCHES NOMINAL IN |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Nut Style | 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 |
|---|---|
| H42M4 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| H42M4 | 5/9 Secondary reference Howmet Global Fastening Systems Inc. Div Microdot Products |
NSN 5310-00-899-9173 is a Nut,self-Locking,extended Washer, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-899-9173 has 1 manufacturer part number on file: H42M4 (Howmet Global Fastening Systems Inc).
Key specifications for H42M4: Lubrication: DRY FILM LUBRICANT; Overall Height: 0.219 INCHES NOMINAL IN; Washer Outside Diameter: 0.420 INCHES NOMINAL IN; Width Across Flats: 0.281 INCHES NOMINAL IN. 13 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.