The Washer,flat, cataloged under National Stock Number 5310-01-188-1690, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. Government technical data includes 13 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-188-1690 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-S-365,GR B FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.870 INCHES MINIMUM AND 0.895 INCHES MAXIMUM IN |
| Precious Material | SILVER |
| Material Document and Classification | QQ-W-321,1/2 HARD FED SPEC 1ST MATERIAL RESPONSE OR QQ-B-626,1/2 HARD FED SPEC 2ND MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Nondefinitive Spec/std Data | A TYPE AND 1 GRADE AND E CLASS |
| Surface Treatment | SILVER OVERALL |
| Precious Material and Location | ALL SURFACES SILVER |
| Peripheral Shape Style | ROUND |
| Material | COPPER ALLOY 270 OR COPPER ALLOY 268 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.505 INCHES MINIMUM AND 0.525 INCHES MAXIMUM IN |
| Thickness | 0.054 INCHES MINIMUM AND 0.074 INCHES MAXIMUM 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 |
|---|---|
| AN961-816S | 2/2 Government specification standardization U.S. Government activity |
| FF-W-92 | 4/1 Identification reference U.S. Government activity |
NSN 5310-01-188-1690 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-01-188-1690: Surface Treatment Document and Classification: QQ-S-365,GR B FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.870 INCHES MINIMUM AND 0.895 INCHES MAXIMUM IN; Precious Material: SILVER; Material Document and Classification: QQ-W-321,1/2 HARD FED SPEC 1ST MATERIAL RESPONSE OR QQ-B-626,1/2 HARD FED SPEC 2ND MATERIAL RESPONSE OVERALL. 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.