The O-Ring, cataloged under National Stock Number 5331-00-565-4978, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. Government technical data includes 6 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5331-00-565-4978 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Status | ACTIVE |
| Cross-Sectional Height | 0.100 INCHES MINIMUM AND 0.106 INCHES MAXIMUM IN |
| Outside Diameter | 7.943 INCHES NOMINAL IN |
| Hardness Rating | 70.0 SHORE DUROMETER A NOMINAL |
| Elongation Percentage | 125 MAXIMUM |
| Center Hole Diameter | 7.692 INCHES MINIMUM AND 7.782 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 |
| Reference | Meaning |
|---|---|
| MILR25988 | 5/9 Secondary reference U.S. Government activity |
| M25988/1-170 | 2/2 Government specification standardization U.S. Government activity |
| MIL-R-25988 TY1 CL1 GR 40 | 5/1 Secondary reference U.S. Government activity |
| MIL-DTL-25988/1 | 4/1 Identification reference U.S. Government activity |
NSN 5331-00-565-4978 is a O-Ring, classified under FSC 5331, O-ring. Status: active.
Key specifications for 5331-00-565-4978: Cross-Sectional Height: 0.100 INCHES MINIMUM AND 0.106 INCHES MAXIMUM IN; Outside Diameter: 7.943 INCHES NOMINAL IN; Hardness Rating: 70.0 SHORE DUROMETER A NOMINAL; 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.