The Gear,spur, cataloged under National Stock Number 3020-01-255-6253, is classified within Federal Supply Class 3020 (Gears, Pulleys, Sprockets, and Transmission Chain) of the Mechanical Power Transmission Equipment group. Government technical data includes 24 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3020-01-255-6253 |
| Item Name | Gear,spur |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Status | ACTIVE |
| Bore Nominal Diameter | 0.516 INCHES FIRST END IN |
| Hub Nominal Diameter | 0.812 INCHES FIRST END IN |
| Teeth Quantity | 12 |
| Body Style | PLAIN, SOLID |
| Bore Style | PLAIN FIRST END |
| Bore Style | THREAD SERIES DESIGNATOR PARTIALLY THREADED SECOND END |
| Nominal Distance Between Body Face and Protruding Hub End | 0.250 INCHES FIRST END IN |
| Hardness Rating | 50.0 ROCKWELL C MINIMUM AND 55.0 ROCKWELL C MAXIMUM OVERALL |
| Criticality Code Justification | ZZZY |
| Style Designator | PROTRUDING HUB |
| Material Document and Classification | QQ-T-870,CLASS 1 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Pitch Diameter | 1.0000 INCHES NOMINAL IN |
| Tooth Form | STANDARD |
| Thread Direction | RIGHT-HAND SECOND END |
| Nominal Thread Size | 0.500 INCHES SECOND END IN |
| Hub Style Designator | PLAIN FIRST END |
| Nominal Outside Diameter | 1.166 INCHES IN |
| Thread Class | 3B SECOND END |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL OVERALL |
| Thread Series Designator | UNF SECOND END |
| Reference Number Differentiating Characteristics | MATERIAL WILL BE IN ACCORDANCE WITH SHIPS PARTS CONTROL CENTER ACTIVITY HX QUALITY CONTROL,MANUFACTURING AND TESTING SPECIFICATIONS |
| Nominal Thread Length | 0.718 INCHES SECOND END IN |
| Face Nominal Width | 0.812 INCHES IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Reference | Meaning |
|---|---|
| 903-5912051 | 5/9 Secondary reference U.S. Government activity |
| 903-5912051 PC14 | 3/9 Design control — primary reference U.S. Government activity |
NSN 3020-01-255-6253 is a Gear,spur, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 5355-01-417-1818, 4730-01-442-8582. Verify interchangeability with system specifications before substitution.
Key specifications for 3020-01-255-6253: Bore Nominal Diameter: 0.516 INCHES FIRST END IN; Hub Nominal Diameter: 0.812 INCHES FIRST END IN; Teeth Quantity: 12; Body Style: PLAIN, SOLID. 24 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.