The O-Ring, cataloged under National Stock Number 5331-01-387-1231, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Sae International Dba Sae International. Government technical data includes 5 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5331-01-387-1231 |
| Primary Part Number | MS9966-20 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Sae International Dba Sae International |
| Status | ACTIVE |
| Cross-Sectional Height | 0.114 INCHES MINIMUM AND 0.122 INCHES MAXIMUM IN |
| Hardness Rating | 70.0 SHORE DUROMETER A MINIMUM AND 80.0 SHORE DUROMETER A MINIMUM |
| Material Document and Classification | AMS 7273 ASSN STD SINGLE MATERIAL RESPONSE |
| Center Hole Diameter | 1.465 INCHES MINIMUM AND 1.485 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 |
|---|---|
| MS9966-20 PRIMARY | Sae International Dba Sae International (USA) |
| Reference | Meaning |
|---|---|
| MS9966-20 | 3/9 Design control — primary reference U.S. Government activity |
| MS9966-20 | 5/9 Secondary reference U.S. Government activity |
| SAE-AS9966 | 3/1 Design control — primary reference Sae International Dba Sae International |
NSN 5331-01-387-1231 is a O-Ring, manufactured by Sae International Dba Sae International, classified under FSC 5331, O-ring. Status: active.
NSN 5331-01-387-1231 has 1 manufacturer part number on file: MS9966-20 (Sae International Dba Sae International).
1 possible match (shared part number, not a government interchangeability claim): 5331-01-511-3072. Verify interchangeability with system specifications before substitution.
Key specifications for MS9966-20: Cross-Sectional Height: 0.114 INCHES MINIMUM AND 0.122 INCHES MAXIMUM IN; Hardness Rating: 70.0 SHORE DUROMETER A MINIMUM AND 80.0 SHORE DUROMETER A MINIMUM; Material Document and Classification: AMS 7273 ASSN STD SINGLE MATERIAL RESPONSE; Center Hole Diameter: 1.465 INCHES MINIMUM AND 1.485 INCHES MAXIMUM IN. 5 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.