The Washer,recessed, cataloged under National Stock Number 5310-00-839-2020, 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10 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-839-2020 |
| Item Name | Washer,recessed |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Hardness Rating | 32.0 ROCKWELL C MINIMUM AND 36.0 ROCKWELL C MAXIMUM |
| Style Designator | RECESSED |
| Material Document and Classification | 66 FED STD 1ST MATERIAL RESPONSE OR AISI ASSN STD 2ND MATERIAL RESPONSE OR 66 FED STD 3RD MATERIAL RESPONSE OVERALL |
| Outside Diameter | 0.505 INCHES MINIMUM AND 0.523 INCHES MAXIMUM IN |
| Recess Depth | 0.153 INCHES MINIMUM AND 0.162 INCHES MAXIMUM IN |
| Material Thickness | 0.104 INCHES MINIMUM AND 0.108 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Material | STEEL COMP 1330 OR STEEL COMP 3130 OR STEEL COMP 4130 OVERALL |
| Hole Diameter | 0.253 INCHES MINIMUM AND 0.259 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 |
|---|---|
| 51210S4 | 5/9 Secondary reference U.S. Government activity |
| AS158-S4 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-00-839-2020 is a Washer,recessed, classified under FSC 5310, Nuts and Washers. Status: active.
Key specifications for 5310-00-839-2020: Overall Height: 0.216 INCHES MINIMUM AND 0.225 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Hardness Rating: 32.0 ROCKWELL C MINIMUM AND 36.0 ROCKWELL C MAXIMUM; Style Designator: RECESSED. 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.