The Washer,flat, cataloged under National Stock Number 5310-01-128-4126, 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 9 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-128-4126 |
| Primary Part Number | 645074-3FW |
| 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 | STM A380 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.302 INCHES MINIMUM AND 0.322 INCHES MAXIMUM IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL CORROSION RESISTING OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.177 INCHES MINIMUM AND 0.197 INCHES MAXIMUM IN |
| Thickness | 0.021 INCHES MINIMUM AND 0.041 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 |
|---|---|
| 645074-3FW | Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA) |
| Reference | Meaning |
|---|---|
| 645074-3F | C/1 Advisory reference — outside the item-of-supply concept U.S. Government activity |
| 10109484 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| 645074-3FW | 3/2 Design control — primary reference U.S. Government activity |
NSN 5310-01-128-4126 is a Washer,flat, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-128-4126 has 1 manufacturer part number on file: 645074-3FW (Ontic Engineering & Manufacturing, Inc Dba Ontic Us).
Key specifications for 645074-3FW: Surface Treatment Document and Classification: STM A380 ASSN STD SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.302 INCHES MINIMUM AND 0.322 INCHES MAXIMUM IN; Cross-Sectional Shape Style: RECTANGULAR; Surface Treatment: PASSIVATE OVERALL. 9 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.