The Gear,spur, cataloged under National Stock Number 3020-01-279-4640, is classified within Federal Supply Class 3020 (Gears, Pulleys, Sprockets, and Transmission Chain) of the Mechanical Power Transmission Equipment group. The manufacturer of record is Mcelroy Marine Machinery. Government technical data includes 12 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 3020-01-279-4640 |
| Primary Part Number | C-1281-83-11 |
| Item Name | Gear,spur |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Manufacturer | Mcelroy Marine Machinery |
| Status | ACTIVE |
| Bore Nominal Diameter | 16.501 INCHES BOTH ENDS IN |
| Teeth Quantity | 62 |
| Body Style | PLAIN, SOLID |
| Bore Style | PLAIN BOTH ENDS |
| Hardness Rating | 360.0 BRINELL HULTGREN MINIMUM OVERALL |
| Style Designator | HUBLESS, RECESSED BODY |
| Pitch Diameter | 31.0000 INCHES NOMINAL IN |
| Nominal Outside Diameter | 32.438 INCHES IN |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL COMP 4140 OVERALL |
| Body Recess Nominal Depth | 2.250 INCHES FIRST END IN |
| Face Nominal Width | 3.250 INCHES IN |
| 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 |
|---|---|
| C-1281-83-11 PRIMARY | Mcelroy Marine Machinery (USA) |
| Reference | Meaning |
|---|---|
| C-1281-85-11 | C/1 Advisory reference — outside the item-of-supply concept Mcelroy Marine Machinery |
| C-1281-85 | D/9 Drawing number reference only Mcelroy Marine Machinery |
NSN 3020-01-279-4640 is a Gear,spur, manufactured by Mcelroy Marine Machinery, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
NSN 3020-01-279-4640 has 1 manufacturer part number on file: C-1281-83-11 (Mcelroy Marine Machinery).
1 possible match (shared part number, not a government interchangeability claim): 3020-01-279-4641. Verify interchangeability with system specifications before substitution.
Key specifications for C-1281-83-11: Bore Nominal Diameter: 16.501 INCHES BOTH ENDS IN; Teeth Quantity: 62; Body Style: PLAIN, SOLID; Bore Style: PLAIN BOTH ENDS. 12 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.