The O-Ring, cataloged under National Stock Number 5331-01-503-1037, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Core Industries Inc. Dba Mueller Steam Specialty. Government technical data includes 1 specification, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5331-01-503-1037 |
| Primary Part Number | 000643125 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Core Industries Inc. Dba Mueller Steam Specialty |
| Status | ACTIVE |
| 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 |
|---|---|
| 2.5-51-23-3 | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
| 000643125 PRIMARY | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
| AN-2.5-51 PART NO.6 | Core Industries Inc. Dba Mueller Steam Specialty (USA) |
NSN 5331-01-503-1037 is a O-Ring, manufactured by Core Industries Inc. Dba Mueller Steam Specialty, classified under FSC 5331, O-ring. Status: active.
NSN 5331-01-503-1037 has 3 manufacturer part numbers on file: 2.5-51-23-3 (Core Industries Inc. Dba Mueller Steam Specialty), 000643125 (Core Industries Inc. Dba Mueller Steam Specialty), AN-2.5-51 PART NO.6 (Core Industries Inc. Dba Mueller Steam Specialty).
Key specifications for 000643125: Part Name Assigned by Controlling Agency: UPPER STEM O-RING,BUNA-N; End Item Identification: 2 1/2 INCH NO.51 BUTTERFLY VALVE HARD SEAT ASSEMBLY IN; Material: RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR. 1 specification is 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.