The Washer,spring Tension, cataloged under National Stock Number 5310-01-030-4918, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 8 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 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 | 5310-01-030-4918 |
| Primary Part Number | ST4M178A2 |
| Item Name | Washer,spring Tension |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-T-10727 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Style Designator | SPRING TENSION |
| Material Document and Classification | QQ-C-533,TEMPER AT FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Outside Diameter | 2.110 INCHES NOMINAL2.110 INCHES NOMINAL IN |
| Material Thickness | 0.016 INCHES NOMINAL0.016 INCHES NOMINAL IN |
| Surface Treatment | TIN OVERALL |
| Material | COPPER ALLOY 172 OVERALL |
| Hole Diameter | 1.650 INCHES NOMINAL1.650 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 |
NSN 5310-01-030-4918 is a Washer,spring Tension, manufactured by The Boeing Company Div Defense, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-030-4918 has 2 manufacturer part numbers on file: ST4M178A2 (The Boeing Company Div Defense), 4M294-28 (Smalley Steel Ring Co.).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-170-9106. Verify interchangeability with system specifications before substitution.
Key specifications for ST4M178A2: Overall Height: 0.368 INCHES NOMINAL0.368 INCHES NOMINAL IN; Surface Treatment Document and Classification: MIL-T-10727 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Style Designator: SPRING TENSION; Material Document and Classification: QQ-C-533,TEMPER AT FED SPEC SINGLE MATERIAL RESPONSE OVERALL. 8 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.