The Washer,flat, cataloged under National Stock Number 5310-01-221-4201, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 3 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-221-4201 |
| Primary Part Number | 2641-405-01 ITEM 39CP |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Material | PLASTIC ACETAL OVERALL |
| Reference Number Differentiating Characteristics | CLEANING, PACKAGING, AND MARKING IAW MIL-STD-1330D |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| 2641-405-01 ITEM 39CP | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 2641-809-40 ITEM 56 | 3/1 Design control — primary reference U.S. Government activity |
| 2641-405-01 ITEM 39 | 5/1 Secondary reference U.S. Government activity |
| 2641-809-40 ITEM 56CP | C/1 Advisory reference — outside the item-of-supply concept Naval Inventory Control Point Mechanicsburg |
NSN 5310-01-221-4201 is a Washer,flat, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-221-4201 has 1 manufacturer part number on file: 2641-405-01 ITEM 39CP (Naval Inventory Control Point Mechanicsburg).
2 possible matches (shared part number, not a government interchangeability claim): 5310-01-474-8822, 5310-01-548-5582. Verify interchangeability with system specifications before substitution.
Key specifications for 2641-405-01 ITEM 39CP: Criticality Code Justification: ZZZY; Material: PLASTIC ACETAL OVERALL; Reference Number Differentiating Characteristics: CLEANING, PACKAGING, AND MARKING IAW MIL-STD-1330D. 3 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.