The Washer,key, cataloged under National Stock Number 5310-01-591-1373, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Sae International Dba Sae International. Government technical data includes 12 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-591-1373 |
| Primary Part Number | MS9581-12 |
| Item Name | Washer,key |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Sae International Dba Sae International |
| Status | ACTIVE |
| Distance From Centerline to Inside of Prebent Key | 0.365 INCHES MINIMUM AND 0.375 INCHES MAXIMUM IN |
| External Prebent Key Length | 0.020 INCHES MINIMUM AND 0.040 INCHES MAXIMUM IN |
| Style Designator | 90 DEGREE LOCKING KEY |
| Material Document and Classification | AMS 5510 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Outside Diameter | 0.560 INCHES MINIMUM AND 0.570 INCHES MAXIMUM IN |
| External Tapered Key Width | 0.320 INCHES MINIMUM AND 0.330 INCHES MAXIMUM IN |
| Material Thickness | 0.005 INCHES NOMINAL IN |
| External Prebent Key Angle | 10.0 DEGREES MINIMUM AND 20.0 DEGREES MAXIMUM |
| External Prebent Key Width | 0.140 INCHES MINIMUM AND 0.145 INCHES MAXIMUM IN |
| Material | STEEL COMP 321 OVERALL |
| Angle Between External Keys | 58.0 DEGREES MINIMUM AND 62.0 DEGREES MAXIMUM |
| Hole Diameter | 0.390 INCHES MINIMUM AND 0.395 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 |
|---|---|
| MS9581-12 PRIMARY | Sae International Dba Sae International (USA) |
| Reference | Meaning |
|---|---|
| AS9581 | 5/9 Secondary reference U.S. Government activity |
| MS9581-12 | 5/9 Secondary reference U.S. Government activity |
| AS9581 | 5/1 Secondary reference Sae International Dba Sae International |
| MS9581-12 | 3/9 Design control — primary reference U.S. Government activity |
NSN 5310-01-591-1373 is a Washer,key, manufactured by Sae International Dba Sae International, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-591-1373 has 1 manufacturer part number on file: MS9581-12 (Sae International Dba Sae International).
Key specifications for MS9581-12: Distance From Centerline to Inside of Prebent Key: 0.365 INCHES MINIMUM AND 0.375 INCHES MAXIMUM IN; External Prebent Key Length: 0.020 INCHES MINIMUM AND 0.040 INCHES MAXIMUM IN; Style Designator: 90 DEGREE LOCKING KEY; Material Document and Classification: AMS 5510 ASSN STD SINGLE MATERIAL RESPONSE OVERALL. 12 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.