The Ring,piston, cataloged under National Stock Number 3040-01-033-2890, is classified within Federal Supply Class 3040 (Miscellaneous Power Transmission Equipment) of the Mechanical Power Transmission Equipment group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 7 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3040-01-033-2890 |
| Primary Part Number | ST7M342-18 |
| Item Name | Ring,piston |
| FSC / FSG | 3040 / 30 — Miscellaneous Power Transmission Equipment |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-C-320,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Material Document and Classification | AMS5621 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Joint Style | VERTICAL/DIAGONAL JOINT |
| Radial Wall Thickness | 0.0440 INCHES NOMINAL IN |
| Ring Style | CONCENTRIC |
| Surface Treatment | CHROMIUM OVERALL |
| Material | STEEL CORROSION RESISTING OVERALL |
| 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 |
|---|---|
| DS8015-18 | Double Seal Ring Co (USA) |
| ST7M342-18 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| J3-8019 | 5/2 Secondary reference U.S. Government activity |
| FR84-18 | 5/2 Secondary reference U.S. Government activity |
NSN 3040-01-033-2890 is a Ring,piston, manufactured by The Boeing Company Div Defense, classified under FSC 3040, Miscellaneous Power Transmission Equipment. Status: active.
NSN 3040-01-033-2890 has 2 manufacturer part numbers on file: DS8015-18 (Double Seal Ring Co), ST7M342-18 (The Boeing Company Div Defense).
Key specifications for ST7M342-18: Surface Treatment Document and Classification: QQ-C-320,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Width: 0.0440 INCHES NOMINAL IN; Material Document and Classification: AMS5621 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Joint Style: VERTICAL/DIAGONAL JOINT. 7 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.