The Washer,flat, cataloged under National Stock Number 5310-01-276-4890, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 11 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-276-4890 |
| Primary Part Number | 123PM10309-511 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TY2,CL2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 1.000 INCHES NOMINAL IN |
| Hardness Rating | 33.0 ROCKWELL C MINIMUM AND 37.0 ROCKWELL C MAXIMUM |
| Material Document and Classification | MIL-S-6758 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 4130 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.256 INCHES MINIMUM AND 0.263 INCHES MAXIMUM IN |
| Thickness | 0.120 INCHES NOMINAL 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 |
|---|---|
| 123PM10309-511 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 123PM10309-511 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
NSN 5310-01-276-4890 is a Washer,flat, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-276-4890 has 1 manufacturer part number on file: 123PM10309-511 (Northrop Grumman Systems Corporation).
Key specifications for 123PM10309-511: Surface Treatment Document and Classification: QQ-P-416,TY2,CL2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 1.000 INCHES NOMINAL IN; Hardness Rating: 33.0 ROCKWELL C MINIMUM AND 37.0 ROCKWELL C MAXIMUM; Material Document and Classification: MIL-S-6758 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL. 11 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.