The Washer,flat, cataloged under National Stock Number 5310-00-770-2181, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 10 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-770-2181 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Overall Diameter | 0.560 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-S-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Color | BLUE OVERALL |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.199 INCHES MINIMUM AND 0.201 INCHES MAXIMUM IN |
| Thickness | 0.020 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 |
| Reference | Meaning |
|---|---|
| 10W020-20C56 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Is Div Northrop Grumman Aeronautics Systems |
| 10W020-20C56 | 5/9 Secondary reference American-Marsh Pumps Inc Novo Pump and Engine Division |
| 10W020-20C56 | C/1 Advisory reference — outside the item-of-supply concept Northrop Grumman Technical Services, Inc. Dba Defense Systems Sector |
NSN 5310-00-770-2181 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-00-770-2181: Overall Diameter: 0.560 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN; Material Document and Classification: MIL-S-5059 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR; Color: BLUE OVERALL. 10 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.