The Washer,flat, cataloged under National Stock Number 5310-01-421-2931, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Anillo Industries Llc. Government technical data includes 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-421-2931 |
| Primary Part Number | S2431218-7D16G |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Anillo Industries Llc |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-C-5541, CL3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.995 INCHES MINIMUM AND 1.020 INCHES MAXIMUM IN |
| Material Document and Classification | QQ-A-250/5 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | CHROMATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | ALUMINUM ALLOY 2024 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.443 INCHES MINIMUM AND 0.463 INCHES MAXIMUM IN |
| Thickness | 0.063 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 |
|---|---|
| S2431218-7D16G | Moeller Manufacturing & Supply, Llc (USA) |
| S2431218-7D16G PRIMARY | Anillo Industries Llc (USA) |
| Reference | Meaning |
|---|---|
| S2441218-7D16G | 5/2 Secondary reference U.S. Government activity |
NSN 5310-01-421-2931 is a Washer,flat, manufactured by Anillo Industries Llc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-421-2931 has 2 manufacturer part numbers on file: S2431218-7D16G (Moeller Manufacturing & Supply, Llc), S2431218-7D16G (Anillo Industries Llc).
Key specifications for S2431218-7D16G: Surface Treatment Document and Classification: MIL-C-5541, CL3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.995 INCHES MINIMUM AND 1.020 INCHES MAXIMUM IN; Material Document and Classification: QQ-A-250/5 FED SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 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.