The Washer,flat, cataloged under National Stock Number 5310-00-166-5407, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Ontic Engineering & Manufacturing, Inc Dba Ontic Us. Government technical data includes 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-166-5407 |
| Primary Part Number | 739-23 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Ontic Engineering & Manufacturing, Inc Dba Ontic Us |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-A-696 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 1.178 INCHES MINIMUM AND 1.183 INCHES MAXIMUM IN |
| Material Document and Classification | QQ-A-351 COND T FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | ANODIZE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | ALUMINUM ALLOY 2017 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.334 INCHES MINIMUM AND 0.354 INCHES MAXIMUM IN |
| Thickness | 0.115 INCHES MINIMUM AND 0.135 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 |
|---|---|
| 739-23 PRIMARY | Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA) |
| Reference | Meaning |
|---|---|
| 739-23 | 5/9 Secondary reference Donallco Inc |
NSN 5310-00-166-5407 is a Washer,flat, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-166-5407 has 1 manufacturer part number on file: 739-23 (Ontic Engineering & Manufacturing, Inc Dba Ontic Us).
1 possible match (shared part number, not a government interchangeability claim): 5310-00-770-2657. Verify interchangeability with system specifications before substitution.
Key specifications for 739-23: Surface Treatment Document and Classification: QQ-A-696 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 1.178 INCHES MINIMUM AND 1.183 INCHES MAXIMUM IN; Material Document and Classification: QQ-A-351 COND T FED SPEC 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.