The Washer,flat, cataloged under National Stock Number 5310-01-070-9643, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Curtiss-Wright Controls, Inc. Dba Curtiss Wright Div Actuation Division. 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 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 | 5310-01-070-9643 |
| Primary Part Number | 180739-4 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Curtiss-Wright Controls, Inc. Dba Curtiss Wright Div Actuation Division |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.750 INCHES NOMINAL IN |
| Hardness Rating | 25.0 ROCKWELL C MINIMUM AND 32.0 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 | 0.270 INCHES NOMINAL IN |
| Thickness | 0.020 INCHES MINIMUM AND 0.030 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 |
|---|---|
| 180739-4 PRIMARY | Curtiss-Wright Controls, Inc. Dba Curtiss Wright Div Actuation Division (USA) |
NSN 5310-01-070-9643 is a Washer,flat, manufactured by Curtiss-Wright Controls, Inc. Dba Curtiss Wright Div Actuation Division, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-070-9643 has 1 manufacturer part number on file: 180739-4 (Curtiss-Wright Controls, Inc. Dba Curtiss Wright Div Actuation Division).
1 possible match (shared part number, not a government interchangeability claim): 5990-01-268-4268. Verify interchangeability with system specifications before substitution.
Key specifications for 180739-4: Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.750 INCHES NOMINAL IN; Hardness Rating: 25.0 ROCKWELL C MINIMUM AND 32.0 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.