The Washer,flat, cataloged under National Stock Number 5310-01-218-4929, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Hamilton Sundstrand Corporation Dba Collins Aerospace. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-218-4929 |
| Primary Part Number | 763721-13 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Hamilton Sundstrand Corporation Dba Collins Aerospace |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.622 INCHES MINIMUM AND 0.628 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 | PASSIVATE 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 | 0.257 INCHES MINIMUM AND 0.263 INCHES MAXIMUM IN |
| Thickness | 0.045 INCHES MINIMUM AND 0.055 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 |
|---|---|
| 763721-13 PRIMARY | Hamilton Sundstrand Corporation Dba Collins Aerospace (USA) |
| Reference | Meaning |
|---|---|
| 1/4S 18-8SS | 5/9 Secondary reference U.S. Government activity |
NSN 5310-01-218-4929 is a Washer,flat, manufactured by Hamilton Sundstrand Corporation Dba Collins Aerospace, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-218-4929 has 1 manufacturer part number on file: 763721-13 (Hamilton Sundstrand Corporation Dba Collins Aerospace).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-274-3259. Verify interchangeability with system specifications before substitution.
Key specifications for 763721-13: Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.622 INCHES MINIMUM AND 0.628 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.