The O-Ring, cataloged under National Stock Number 5331-00-324-7730, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 6 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5331-00-324-7730 |
| Primary Part Number | ST7M251-8 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Cross-Sectional Height | 0.023 INCHES MINIMUM AND 0.027 INCHES MAXIMUM IN |
| Hardness Rating | 70.0 SHORE DUROMETER A NOMINAL |
| Material Document and Classification | MIL-R-25988 TYPE 1, CLASS 1, GRADE 70 MIL SPEC SINGLE MATERIAL RESPONSE |
| Elongation Percentage | 125 MAXIMUM |
| Center Hole Diameter | 0.234 INCHES MINIMUM AND 0.244 INCHES MAXIMUM IN |
| Material | RUBBER FLUOROSILICONE CLASS FQ |
| 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 |
|---|---|
| 7583-8 | Hutchinson Seal De Mexico Stillman Seal Division Div Stillman Seal,jpr,espa (MEX) |
| 9950-605A | Parco, Llc (USA) |
| ST7M251-8 | Parco, Llc (USA) |
| ST7M251-8 | Freudenberg-Nok General Partnership Dba International Seal Co Inc (USA) |
| ST7M251-8 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| ST7M251-8 | 5/2 Secondary reference U.S. Government activity |
| 10163280 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| SZ7583-8 | 5/9 Secondary reference U.S. Government activity |
| MIL-R-25988 | 4/1 Identification reference U.S. Government activity |
| 00239-025 F70 | C/1 Advisory reference — outside the item-of-supply concept Freudenberg-Nok General Partnership Dba International Seal Co Inc |
| ST7M251-8 | 5/2 Secondary reference U.S. Government activity |
| CGR1601-0125-8 | 5/9 Secondary reference U.S. Government activity |
| LRC63047-8 | 5/9 Secondary reference Loadholtz Rubber Co Inc |
NSN 5331-00-324-7730 is a O-Ring, manufactured by The Boeing Company Div Defense, classified under FSC 5331, O-ring. Status: active.
NSN 5331-00-324-7730 has 5 manufacturer part numbers on file: 7583-8 (Hutchinson Seal De Mexico Stillman Seal Division Div Stillman Seal,jpr,espa), 9950-605A (Parco, Llc), ST7M251-8 (Parco, Llc), ST7M251-8 (Freudenberg-Nok General Partnership Dba International Seal Co Inc), ST7M251-8 (The Boeing Company Div Defense).
1 possible match (shared part number, not a government interchangeability claim): 5360-00-998-4886. Verify interchangeability with system specifications before substitution.
Key specifications for ST7M251-8: Cross-Sectional Height: 0.023 INCHES MINIMUM AND 0.027 INCHES MAXIMUM IN; Hardness Rating: 70.0 SHORE DUROMETER A NOMINAL; Material Document and Classification: MIL-R-25988 TYPE 1, CLASS 1, GRADE 70 MIL SPEC SINGLE MATERIAL RESPONSE; Elongation Percentage: 125 MAXIMUM. 6 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.