The Washer,flat, cataloged under National Stock Number 5310-01-129-4375, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp. Government technical data includes 10 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 | 5310-01-129-4375 |
| Primary Part Number | SS4409-053 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-C-13924 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.495 INCHES MINIMUM AND 0.520 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-S-5059 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 4TH MATERIAL RESPONSE OR AMS 5510 ASSN STD 5TH MATERIAL RESPONSE OR AMS 5512 ASSN STD 6TH MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | OXIDE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 301 OR STEEL COMP 302 OR STEEL COMP 304 OR STEEL COMP 316 OR STEEL COMP 321 OR STEEL COMP 347 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.255 INCHES MINIMUM AND 0.270 INCHES MAXIMUM IN |
| Thickness | 0.013 INCHES MINIMUM AND 0.019 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 |
|---|---|
| SS4409-053 PRIMARY | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
NSN 5310-01-129-4375 is a Washer,flat, manufactured by Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-129-4375 has 1 manufacturer part number on file: SS4409-053 (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp).
Key specifications for SS4409-053: Surface Treatment Document and Classification: MIL-C-13924 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.495 INCHES MINIMUM AND 0.520 INCHES MAXIMUM IN; Material Document and Classification: MIL-S-5059 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 3RD MATERIAL RESPONSE OR MIL-S-5059 MIL SPEC 4TH MATERIAL RESPONSE OR AMS 5510 ASSN STD 5TH MATERIAL RESPONSE OR AMS 5512 ASSN STD 6TH MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 10 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.