The Washer,flat, cataloged under National Stock Number 5310-01-550-3505, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Hdt Expeditionary Systems, Inc. Dba Hdt Tactical Systems Inc. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 2 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-550-3505 |
| Primary Part Number | HRWBLK |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Hdt Expeditionary Systems, Inc. Dba Hdt Tactical Systems Inc |
| Status | ACTIVE |
| Color | BLACK OVERALL |
| Material | STEEL OVERALL |
| Thickness | 0.050 INCHES MINIMUM AND 0.081 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 |
|---|---|
| HRWBLK PRIMARY | Hdt Expeditionary Systems, Inc. Dba Hdt Tactical Systems Inc (USA) |
| 25N125WFEY/DEL-MKS | Old Dominion Fasteners, Inc (USA) |
| Reference | Meaning |
|---|---|
| HRWBLK | 5/9 Secondary reference Hdt Expeditionary Systems, Inc. |
| 25N125WFEY/DEY-MKS | 5/9 Secondary reference Old Dominion Fasteners, Inc |
NSN 5310-01-550-3505 is a Washer,flat, manufactured by Hdt Expeditionary Systems, Inc. Dba Hdt Tactical Systems Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-550-3505 has 2 manufacturer part numbers on file: HRWBLK (Hdt Expeditionary Systems, Inc. Dba Hdt Tactical Systems Inc), 25N125WFEY/DEL-MKS (Old Dominion Fasteners, Inc).
Key specifications for HRWBLK: Color: BLACK OVERALL; Special Features: INNER DIAMETER-0.281 IN; OUTER DIAMETER-1.250 IN IN; Part Name Assigned by Controlling Agency: WASHER,FENDER,1/4X1-1/4,ZY W/BLK DELTA; End Item Identification: ARMORED MULTI-PURPOSE VEHICLE (AMPV). 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.