The Piston,internal Combustion Engin, cataloged under National Stock Number 2805-00-374-4989, 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 Brinkley Technology Group Llc Dba Hercules Manufacturing. Government technical data includes 25 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2805-00-374-4989 |
| Primary Part Number | 21139AS |
| Item Name | Piston,internal Combustion Engin |
| FSC / FSG | 2805 / 28 — Gasoline Reciprocating Engines, Except Aircraft; and Components |
| Manufacturer | Brinkley Technology Group Llc Dba Hercules Manufacturing |
| Status | ACTIVE |
| FSC Application Data | ENGINE,GASOLINE,NONAIRCRAFT |
| Carbon Groove | NOT INCLUDED |
| Ring Groove Width | 0.0975 INCHES NOMINAL FIRST RING IN |
| Ring Groove Width | 0.1275 INCHES NOMINAL SECOND RING IN |
| Ring Groove Width | 0.2515 INCHES NOMINAL THIRD RING IN |
| Distance Between Pin Bosses | 2.469 INCHES NOMINAL IN |
| Retaining Ring Groove | INCLUDED |
| Surface Finish | FINISHED |
| Diameter | 4.250 INCHES NOMINAL IN |
| Ring Groove Diameter | 3.775 INCHES NOMINAL FIRST RING IN |
| Ring Groove Diameter | 3.805 INCHES NOMINAL THIRD RING IN |
| Ring Groove Diameter | 3.845 INCHES NOMINAL SECOND RING IN |
| Distance From Pin Hole Center to Extreme Top | 2.253 INCHES NOMINAL IN |
| Pin | INCLUDED |
| Pin Type for Which Designed | FLOATING |
| Oil Groove | NOT INCLUDED |
| Head Style | HUMP |
| Ring Groove Quantity | 3 |
| Skirt Bottom Cutaway Feature | NOT INCLUDED |
| Finished Size Designation | STANDARD |
| Ring | INCLUDED |
| Pinhole Diameter | 1.3125 INCHES NOMINAL IN |
| Pin Hole Bushing | NOT INCLUDED |
| Material | ALUMINUM |
| Skirt Type | SOLID |
| 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 |
|---|---|
| 21139AS PRIMARY | Brinkley Technology Group Llc Dba Hercules Manufacturing (USA) |
| Reference | Meaning |
|---|---|
| 21139AS | 5/9 Secondary reference Hercules Engine Co Inc |
NSN 2805-00-374-4989 is a Piston,internal Combustion Engin, manufactured by Brinkley Technology Group Llc Dba Hercules Manufacturing, classified under FSC 2805, Gasoline Reciprocating Engines, Except Aircraft; and Components. Status: active.
NSN 2805-00-374-4989 has 1 manufacturer part number on file: 21139AS (Brinkley Technology Group Llc Dba Hercules Manufacturing).
Key specifications for 21139AS: Overall Height: 4.000 INCHES NOMINAL IN; FSC Application Data: ENGINE,GASOLINE,NONAIRCRAFT; Carbon Groove: NOT INCLUDED; Ring Groove Width: 0.0975 INCHES NOMINAL FIRST RING IN. 25 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.