The Bearing,plain,self-Aligning, cataloged under National Stock Number 3120-01-348-8581, is classified within Federal Supply Class 3120 (Bearings, Plain, Unmounted) of the Bearings group. Government technical data includes 17 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 3120-01-348-8581 |
| Item Name | Bearing,plain,self-Aligning |
| FSC / FSG | 3120 / 31 — Bearings, Plain, Unmounted |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-C-320 FED SPEC SINGLE TREATMENT RESPONSE INNER MEMBER |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OUTER RACE MEMBER |
| Inner Member Width | 0.3410 INCHES MINIMUM AND 0.3430 INCHES MAXIMUM IN |
| Hardness Rating | 56.0 ROCKWELL C MINIMUM INNER MEMBER |
| Hardness Rating | 27.0 ROCKWELL C MINIMUM AND 36.0 ROCKWELL C MAXIMUM OUTER RACE MEMBER |
| Outer Member Width | 0.2450 INCHES MINIMUM AND 0.2550 INCHES MAXIMUM IN |
| Style Designator | WITHOUT INSERT OR LINER |
| Material Document and Classification | AMS 5630 ASSN STD SINGLE MATERIAL RESPONSE INNER MEMBER |
| Material Document and Classification | MIL-G-21164 MIL SPEC SINGLE MATERIAL RESPONSE LUBRICATION |
| Surface Treatment | CADMIUM AND CHROMATE OUTER RACE MEMBER |
| Surface Treatment | CHROMIUM INNER MEMBER |
| Static Radial Load Rating | 4300 POUNDS LBS |
| Bore Diameter | 0.2495 INCHES MINIMUM AND 0.2500 INCHES MAXIMUM IN |
| Material | COPPER ALLOY OUTER RACE MEMBER |
| Material | STEEL COMP 440C INNER MEMBER |
| Material | GREASE AND DISULFIDE MOLYBDENUM LUBRICATION |
| Outer Member Outside Diameter | 0.6557 INCHES MINIMUM AND 0.6562 INCHES MAXIMUM IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | N |
| Reference | Meaning |
|---|---|
| MS21154 | 4/1 Identification reference U.S. Government activity |
| MS21154B4 | 2/2 Government specification standardization U.S. Government activity |
NSN 3120-01-348-8581 is a Bearing,plain,self-Aligning, classified under FSC 3120, Bearings, Plain, Unmounted. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 3120-01-356-3229. Verify interchangeability with system specifications before substitution.
Key specifications for 3120-01-348-8581: Surface Treatment Document and Classification: QQ-C-320 FED SPEC SINGLE TREATMENT RESPONSE INNER MEMBER; Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OUTER RACE MEMBER; Inner Member Width: 0.3410 INCHES MINIMUM AND 0.3430 INCHES MAXIMUM IN; Hardness Rating: 56.0 ROCKWELL C MINIMUM INNER MEMBER. 17 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.