The Washer,flat, cataloged under National Stock Number 5310-01-186-1258, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Lockheed Martin Corp Electronics and Missiles Div. Government technical data includes 9 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-186-1258 |
| Primary Part Number | 240638 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Lockheed Martin Corp Electronics and Missiles Div |
| Status | ACTIVE |
| Overall Diameter | 0.307 INCHES MINIMUM AND 0.332 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-S-7952 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | DEE |
| Width | 0.252 INCHES MINIMUM AND 0.267 INCHES MAXIMUM IN |
| Material | STEEL OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.125 INCHES NOMINAL IN |
| Thickness | 0.032 INCHES NOMINAL IN |
| 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 |
|---|---|
| 240638 PRIMARY | Lockheed Martin Corp Electronics and Missiles Div (USA) |
NSN 5310-01-186-1258 is a Washer,flat, manufactured by Lockheed Martin Corp Electronics and Missiles Div, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-186-1258 has 1 manufacturer part number on file: 240638 (Lockheed Martin Corp Electronics and Missiles Div).
Key specifications for 240638: Overall Diameter: 0.307 INCHES MINIMUM AND 0.332 INCHES MAXIMUM IN; Material Document and Classification: MIL-S-7952 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: DEE. 9 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.