The O-Ring, cataloged under National Stock Number 5331-00-720-2139, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Metrex Valve Corp. Dba Metrex Valve Corp. Government technical data includes 2 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5331-00-720-2139 |
| Primary Part Number | 5M20 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Metrex Valve Corp. Dba Metrex Valve Corp |
| Status | ACTIVE |
| Cross-Sectional Height | 0.156 INCHES NOMINAL IN |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR |
| 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 |
|---|---|
| 5M20 PRIMARY | Metrex Valve Corp. Dba Metrex Valve Corp (USA) |
| 4K1-25 | Metrex Valve Corp. Dba Metrex Valve Corp (USA) |
| Reference | Meaning |
|---|---|
| 5904-3136437REVJPC63 | 5/2 Secondary reference U.S. Government activity |
| NHPB11199PC63 | 5/9 Secondary reference Metrex Valve Corp. Dba Metrex Valve Corp |
| 5M20PCALL | 5/9 Secondary reference Metrex Valve Corp. Dba Metrex Valve Corp |
NSN 5331-00-720-2139 is a O-Ring, manufactured by Metrex Valve Corp. Dba Metrex Valve Corp, classified under FSC 5331, O-ring. Status: active.
NSN 5331-00-720-2139 has 2 manufacturer part numbers on file: 5M20 (Metrex Valve Corp. Dba Metrex Valve Corp), 4K1-25 (Metrex Valve Corp. Dba Metrex Valve Corp).
1 possible match (shared part number, not a government interchangeability claim): 6135-00-728-9859. Verify interchangeability with system specifications before substitution.
Key specifications for 5M20: Cross-Sectional Height: 0.156 INCHES NOMINAL IN; End Item Identification: ELECTRIC ACTUATED SEAWATER REGULATING VALVE; TIGONDEROGA CLASS CG(47); Material: RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR. 2 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.