The Nut,self-Locking,plate, cataloged under National Stock Number 5310-00-409-9551, 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 21 specifications, cited from the U.S. Government catalog. The record lists 2 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-409-9551 |
| Primary Part Number | MK1031-4 |
| Item Name | Nut,self-Locking,plate |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Plate Thickness | 0.040 INCHES NOMINAL IN |
| Nut Length | 0.786 INCHES MAXIMUM IN |
| Thread Series | UNF |
| Plate Width | 0.414 INCHES MAXIMUM IN |
| Temp Rating | 900.0 FAHRENHEIT NOMINAL DEGF |
| Mounting Hole Arrangement Style | 2 HOLES |
| Material Document and Classification | AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Mounting Hole Diameter | 0.098 INCHES MINIMUM AND 0.103 INCHES MAXIMUM IN |
| Nut Counterbore Depth | 0.062 INCHES MINIMUM NUT IN |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Counterbore Diameter | 0.254 INCHES MINIMUM NUT IN |
| Distance From Aperture Center to Mounting Hole Center | 0.276 INCHES MINIMUM AND 0.286 INCHES MAXIMUM IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Center to Center Distance Between Mounting Holes Along Length | 0.560 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Nut Height | 0.281 INCHES MAXIMUM IN |
| Nut Style | PLATE |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Nut Mounting Provision | STRAIGHT HOLES |
| 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 |
|---|---|
| MK1031-4 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| 641834 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| MK1031-4 | 5/9 Secondary reference Howmet Global Fastening Systems Inc. Div Microdot Products |
NSN 5310-00-409-9551 is a Nut,self-Locking,plate, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-409-9551 has 2 manufacturer part numbers on file: MK1031-4 (Howmet Global Fastening Systems Inc), 641834 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
1 possible match (shared part number, not a government interchangeability claim): 5310-00-703-8304. Verify interchangeability with system specifications before substitution.
Key specifications for MK1031-4: Plate Thickness: 0.040 INCHES NOMINAL IN; Nut Length: 0.786 INCHES MAXIMUM IN; Thread Series: UNF; Plate Width: 0.414 INCHES MAXIMUM IN. 21 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.