The Ring,piston, cataloged under National Stock Number 2805-01-280-8959, is classified within Federal Supply Class 2805 (Gasoline Reciprocating Engines, Except Aircraft; and Components) of the Engines, Turbines, and Components group. The manufacturer of record is Greg-Co Piston Rings Inc. Government technical data includes 5 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 | 2805-01-280-8959 |
| Primary Part Number | R-20538 |
| Item Name | Ring,piston |
| FSC / FSG | 2805 / 28 — Gasoline Reciprocating Engines, Except Aircraft; and Components |
| Manufacturer | Greg-Co Piston Rings Inc |
| Status | ACTIVE |
| Cross-Sectional Shape Style | INSIDE COUNTERBORE, STRAIGHT FACE |
| Joint Style | VERTICAL JOINT |
| Radial Wall Thickness | 0.0620 INCHES NOMINAL IN |
| Ring Style | CONCENTRIC |
| Standard Bore Diameter | 3.500 INCHES 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 |
|---|---|
| R-20538 PRIMARY | Greg-Co Piston Rings Inc (USA) |
NSN 2805-01-280-8959 is a Ring,piston, manufactured by Greg-Co Piston Rings Inc, classified under FSC 2805, Gasoline Reciprocating Engines, Except Aircraft; and Components. Status: active.
NSN 2805-01-280-8959 has 1 manufacturer part number on file: R-20538 (Greg-Co Piston Rings Inc).
Key specifications for R-20538: Overall Width: 0.0920 INCHES NOMINAL IN; Cross-Sectional Shape Style: INSIDE COUNTERBORE, STRAIGHT FACE; Joint Style: VERTICAL JOINT; Radial Wall Thickness: 0.0620 INCHES NOMINAL IN. 5 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.