The Washer,flat, cataloged under National Stock Number 5310-00-121-8322, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Brp Us Inc. Government technical data includes 8 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-121-8322 |
| Primary Part Number | 300721 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Brp Us Inc |
| Status | ACTIVE |
| Overall Diameter | 0.552 INCHES MINIMUM AND 0.572 INCHES MAXIMUM IN |
| Material Document and Classification | QQ-S-766 FED SPEC SINGLE MATERIAL RESPONSE OR QQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 430 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.261 INCHES MINIMUM AND 0.273 INCHES MAXIMUM IN |
| Thickness | 0.044 INCHES MINIMUM AND 0.056 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 |
| Part Number | Manufacturer |
|---|---|
| 300721 PRIMARY | Brp Us Inc (USA) |
| Reference | Meaning |
|---|---|
| 300721 | 5/9 Secondary reference Outboard Marine Corp Johnson Motors Div |
NSN 5310-00-121-8322 is a Washer,flat, manufactured by Brp Us Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-121-8322 has 1 manufacturer part number on file: 300721 (Brp Us Inc).
2 possible matches (shared part number, not a government interchangeability claim): 5925-00-543-7342, 5970-01-396-4221. Verify interchangeability with system specifications before substitution.
Key specifications for 300721: Overall Diameter: 0.552 INCHES MINIMUM AND 0.572 INCHES MAXIMUM IN; Material Document and Classification: QQ-S-766 FED SPEC SINGLE MATERIAL RESPONSE OR QQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR; Peripheral Shape Style: ROUND. 8 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.