The Washer,flat, cataloged under National Stock Number 5310-01-591-4638, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Morito Scovill Americas, Llc Dba Scovill Manufacturing. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-591-4638 |
| Primary Part Number | 91-BS-78505-2C |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Morito Scovill Americas, Llc Dba Scovill Manufacturing |
| Status | ACTIVE |
| Center Hole Width | 0.660 INCHES NOMINAL IN |
| Center Hole Length | 0.660 INCHES NOMINAL IN |
| Length | 1.000 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Outside Radius | 0.770 INCHES NOMINAL IN |
| Peripheral Shape Style | ELLIPTICAL |
| Width | 0.410 INCHES NOMINAL IN |
| Material | COPPER ALLOY OVERALL |
| Center Hole Shape Style | ELLIPTICAL |
| Thickness | 0.015 INCHES NOMINAL IN |
| Inside Radius | 0.344 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 |
|---|---|
| 91-BS-78505-2C PRIMARY | Morito Scovill Americas, Llc Dba Scovill Manufacturing (USA) |
| Reference | Meaning |
|---|---|
| 9D0182-4 | 5/2 Secondary reference U.S. Government activity |
| 9D0182-4 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
NSN 5310-01-591-4638 is a Washer,flat, manufactured by Morito Scovill Americas, Llc Dba Scovill Manufacturing, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-591-4638 has 1 manufacturer part number on file: 91-BS-78505-2C (Morito Scovill Americas, Llc Dba Scovill Manufacturing).
Key specifications for 91-BS-78505-2C: Center Hole Width: 0.660 INCHES NOMINAL IN; Center Hole Length: 0.660 INCHES NOMINAL IN; Length: 1.000 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR. 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.