The Washer,flat, cataloged under National Stock Number 5310-01-539-9991, 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13 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-539-9991 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Status | ACTIVE |
| Surface Finish | 0.1 MICROMETERS ALL SURFACES |
| Surface Treatment Document and Classification | MIL-C-13924 MIL STD SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.745 INCHES MINIMUM AND 0.770 INCHES MAXIMUM IN |
| Material Document and Classification | ASTM-A109, TEMPER 2 (55 KSI MIN UTS) NATIONAL SPEC SINGLE MATERIAL RESPONSE OR MIL-S-7952 MIL STD SINGLE MATERIAL RESPONSE OR MIL-S-1025 MIL STD SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE OVERALL |
| Environmental Protection | CORROSION RESISTANT |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 1020 OR STEEL UNS K02500 OR STEEL COMP 1025 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.443 INCHES MINIMUM AND 0.463 INCHES MAXIMUM IN |
| Thickness | 0.059 INCHES MINIMUM AND 0.067 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 |
|---|---|
| NAS1149 | 3/1 Design control — primary reference U.S. Government activity |
| NAS1149F0763B | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-539-9991 is a Washer,flat, classified under FSC 5310, Nuts and Washers. Status: active.
5 possible matches (shared part number, not a government interchangeability claim): 5310-01-542-3107, 5310-01-551-3763, 5310-01-667-1839. Verify interchangeability with system specifications before substitution.
Key specifications for 5310-01-539-9991: Surface Finish: 0.1 MICROMETERS ALL SURFACES; Surface Treatment Document and Classification: MIL-C-13924 MIL STD SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.745 INCHES MINIMUM AND 0.770 INCHES MAXIMUM IN; Material Document and Classification: ASTM-A109, TEMPER 2 (55 KSI MIN UTS) NATIONAL SPEC SINGLE MATERIAL RESPONSE OR MIL-S-7952 MIL STD SINGLE MATERIAL RESPONSE OR MIL-S-1025 MIL STD SINGLE 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.