The Gear,helical, cataloged under National Stock Number 3020-01-389-9651, 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 Cummins Inc.. Government technical data includes 18 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3020-01-389-9651 |
| Primary Part Number | 3968521 |
| Item Name | Gear,helical |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Manufacturer | Cummins Inc. |
| Status | ACTIVE |
| Bore Nominal Diameter | 22.887 MILLIMETERS FIRST END MM |
| Helix Angle | 15.0000 DEGREES |
| Hub Nominal Diameter | 66.00 MILLIMETERS FIRST END MM |
| Teeth Quantity | 72 |
| Body Style | WEBBED, SOLID |
| Tooth Direction | LEFT |
| Bore Style | PLAIN FIRST END |
| Nominal Distance Between Body Face and Protruding Hub End | 10.0 MILLIMETERS FIRST END MM |
| Teeth Type | SINGLE HELIX |
| Hardness Rating | 45.0 ROCKWELL C MINIMUM AND 52.0 ROCKWELL C MAXIMUM OVERALL |
| Style Designator | PROTRUDING HUB, RECESSED BODY |
| Pitch Diameter | 186.350 MILLIMETERS NOMINAL MM |
| Hub Style Designator | PLAIN FIRST END |
| Nominal Outside Diameter | 191.350 MILLIMETERS MM |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL OVERALL |
| Body Recess Nominal Depth | 5.00 MILLIMETERS SECOND END MM |
| Face Nominal Width | 18.00 MILLIMETERS MM |
| 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 |
|---|---|
| 3968521 PRIMARY | Cummins Inc. (USA) |
| Reference | Meaning |
|---|---|
| 3914622 | 5/9 Secondary reference Cummins Inc. |
| 3929033 | C/1 Advisory reference — outside the item-of-supply concept Cummins Inc. |
NSN 3020-01-389-9651 is a Gear,helical, manufactured by Cummins Inc., classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
NSN 3020-01-389-9651 has 1 manufacturer part number on file: 3968521 (Cummins Inc.).
Key specifications for 3968521: Bore Nominal Diameter: 22.887 MILLIMETERS FIRST END MM; Helix Angle: 15.0000 DEGREES; Hub Nominal Diameter: 66.00 MILLIMETERS FIRST END MM; Teeth Quantity: 72. 18 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.