The Washer,flat, cataloged under National Stock Number 5310-01-321-2439, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is West Coast Lockwasher Co., Inc. Dba West Coast Lockwasher Co Inc Div West Coast Lockwasher. Government technical data includes 10 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-321-2439 |
| Primary Part Number | BACW10BN6SP |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | West Coast Lockwasher Co., Inc. Dba West Coast Lockwasher Co Inc Div West Coast Lockwasher |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.725 INCHES MINIMUM AND 0.745 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | IRON ALLOY 660 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.376 INCHES MINIMUM AND 0.387 INCHES MAXIMUM IN |
| Thickness | 0.057 INCHES MINIMUM AND 0.069 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 |
|---|---|
| BACW10BN6SP | West Coast Lockwasher Co., Inc. Dba West Coast Lockwasher Co Inc Div West Coast Lockwasher (USA) |
| BACW10BN6SP | Anillo Industries Llc (USA) |
| BACW10BN6SP | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| BACW10BN6SP | 3/2 Design control — primary reference U.S. Government activity |
| BACW10BN6SP | 5/9 Secondary reference Mamco Mfg Co Inc |
NSN 5310-01-321-2439 is a Washer,flat, manufactured by West Coast Lockwasher Co., Inc. Dba West Coast Lockwasher Co Inc Div West Coast Lockwasher, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-321-2439 has 3 manufacturer part numbers on file: BACW10BN6SP (West Coast Lockwasher Co., Inc. Dba West Coast Lockwasher Co Inc Div West Coast Lockwasher), BACW10BN6SP (Anillo Industries Llc), BACW10BN6SP (Sps Technologies, Llc Dba PB Fasteners).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-669-4586. Verify interchangeability with system specifications before substitution.
Key specifications for BACW10BN6SP: Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.725 INCHES MINIMUM AND 0.745 INCHES MAXIMUM IN; Material Document and Classification: AMS 5525 ASSN STD 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.