The Washer,flat, cataloged under National Stock Number 5310-01-116-1209, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-116-1209 |
| Primary Part Number | 409B191 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division |
| Status | ACTIVE |
| Overall Diameter | 0.590 INCHES NOMINAL IN |
| Hardness Rating | 50.0 ROCKWELL C MINIMUM |
| Material Document and Classification | MIL-S-46850,TY 3,GRADE 300 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 4130 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.252 INCHES MINIMUM AND 0.257 INCHES MAXIMUM IN |
| Thickness | 0.095 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 |
|---|---|
| 409B191 PRIMARY | Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division (USA) |
| Reference | Meaning |
|---|---|
| 10109288 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| 409B191 | 5/9 Secondary reference Eaton Motor Site |
NSN 5310-01-116-1209 is a Washer,flat, manufactured by Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-116-1209 has 1 manufacturer part number on file: 409B191 (Eaton Aerospace Llc Dba Eaton Inoac Div Fuel & Motion Control Systems Division).
Key specifications for 409B191: Overall Diameter: 0.590 INCHES NOMINAL IN; Hardness Rating: 50.0 ROCKWELL C MINIMUM; Material Document and Classification: MIL-S-46850,TY 3,GRADE 300 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 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.