The Washer,flat, cataloged under National Stock Number 5310-01-028-0790, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Semco Instruments Inc Div Atlas-Aero Corp., Division of Semco Instruments, Inc.. Government technical data includes 6 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-028-0790 |
| Primary Part Number | A1246-16 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Semco Instruments Inc Div Atlas-Aero Corp., Division of Semco Instruments, Inc. |
| Status | ACTIVE |
| Overall Diameter | 0.677 INCHES MINIMUM AND 0.687 INCHES MAXIMUM IN |
| Material Document and Classification | T6 ASSN STD SINGLE MATERIAL RESPONSE OR T4 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Peripheral Shape Style | ROUND |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.358 INCHES MINIMUM AND 0.364 INCHES MAXIMUM IN |
| Thickness | 0.020 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 |
|---|---|
| A1246-16 PRIMARY | Semco Instruments Inc Div Atlas-Aero Corp., Division of Semco Instruments, Inc. (USA) |
NSN 5310-01-028-0790 is a Washer,flat, manufactured by Semco Instruments Inc Div Atlas-Aero Corp., Division of Semco Instruments, Inc., classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-028-0790 has 1 manufacturer part number on file: A1246-16 (Semco Instruments Inc Div Atlas-Aero Corp., Division of Semco Instruments, Inc.).
Key specifications for A1246-16: Overall Diameter: 0.677 INCHES MINIMUM AND 0.687 INCHES MAXIMUM IN; Material Document and Classification: T6 ASSN STD SINGLE MATERIAL RESPONSE OR T4 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Peripheral Shape Style: ROUND; Part Name Assigned by Controlling Agency: NAVY SPECIAL PROJECT. 6 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.