The Washer,spring Tension, cataloged under National Stock Number 5310-01-030-4921, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Tech-Etch, Inc. Dba Tech-Etch Inc. Government technical data includes 8 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-030-4921 |
| Primary Part Number | ST4M178A5 |
| Item Name | Washer,spring Tension |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Tech-Etch, Inc. Dba Tech-Etch Inc |
| 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,TAT FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Outside Diameter | 3.330 INCHES NOMINAL3.330 INCHES NOMINAL IN |
| Material Thickness | 0.025 INCHES NOMINAL0.025 INCHES NOMINAL IN |
| Surface Treatment | TIN OVERALL |
| Material | COPPER ALLOY 172 OVERALL |
| Hole Diameter | 2.870 INCHES NOMINAL2.870 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 |
|---|---|
| ST4M178A5 PRIMARY | Tech-Etch, Inc. Dba Tech-Etch Inc (USA) |
| Reference | Meaning |
|---|---|
| STAM178A5 | 5/9 Secondary reference U.S. Government activity |
| ST4M178A5 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
NSN 5310-01-030-4921 is a Washer,spring Tension, manufactured by Tech-Etch, Inc. Dba Tech-Etch Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-030-4921 has 1 manufacturer part number on file: ST4M178A5 (Tech-Etch, Inc. Dba Tech-Etch Inc).
Key specifications for ST4M178A5: Overall Height: 0.307 INCHES NOMINAL0.307 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,TAT 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.