The Piston,valve-Selector, cataloged under National Stock Number 2520-01-239-1174, is classified within Federal Supply Class 2520 (Vehicular Power Transmission Components) of the Vehicular Equipment Components group. The manufacturer of record is Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic. Government technical data includes 3 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 2520-01-239-1174 |
| Primary Part Number | 212449 |
| Item Name | Piston,valve-Selector |
| FSC / FSG | 2520 / 25 — Vehicular Power Transmission Components |
| Manufacturer | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic |
| Status | ACTIVE |
| Relationship to Similar Equipment | SIMILAR TO NSN 2520-00-153-8732 P/N 202241 |
| General Characteristics Item Description | STEEL SAE 1117; CASEHARDENED; 1.070 IN. O/A LG; 0.875 INSIDE SLEEVE LG; 1.248 IN. MIN 1.249 IN. MAX OD; 1.203 IN. STEP OD; 1.062 IN. SLEEVE ID,8 GROOVES 0.050 IN. W AND 1.203 IN. DIA; 0.250 IN. W BY 0.062 IN. DP SLOTS SLEEVE END IN |
| Functional Description | REGULATING PISTON |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
NSN 2520-01-239-1174 is a Piston,valve-Selector, manufactured by Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic, classified under FSC 2520, Vehicular Power Transmission Components. Status: active.
NSN 2520-01-239-1174 has 2 manufacturer part numbers on file: 212449 (Marine & Industrial Transmissions Ltd), 212449 (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic).
Key specifications for 212449: Relationship to Similar Equipment: SIMILAR TO NSN 2520-00-153-8732 P/N 202241; General Characteristics Item Description: STEEL SAE 1117; CASEHARDENED; 1.070 IN. O/A LG; 0.875 INSIDE SLEEVE LG; 1.248 IN. MIN 1.249 IN. MAX OD; 1.203 IN. STEP OD; 1.062 IN. SLEEVE ID,8 GROOVES 0.050 IN. W AND 1.203 IN. DIA; 0.250 IN. W BY 0.062 IN. DP SLOTS SLEEVE END IN; Functional Description: REGULATING PISTON; End Item Identification: TWIN DISC HYDRAULIC TRANSMISSION MODEL TDC-20-2800. 3 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.