The Gear,helical, cataloged under National Stock Number 3020-00-423-9985, 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 Caterpillar Inc Div Caterpillar Defense. Government technical data includes 21 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3020-00-423-9985 |
| Primary Part Number | 6B9537 |
| Item Name | Gear,helical |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Manufacturer | Caterpillar Inc Div Caterpillar Defense |
| Status | ACTIVE |
| Bore Nominal Diameter | 21.226 INCHES COUNTERBORE FIRST END IN |
| Helix Angle | 15.4083 DEGREES |
| Teeth Quantity | 139 |
| Body Style | PLAIN, SOLID |
| Counterbore Nominal Diameter | 23.000 INCHES COUNTERBORE FIRST END IN |
| Tooth Direction | LEFT |
| Bore Style | W/COUNTERBORE COUNTERBORE FIRST END |
| Mounting Hole Type and Quantity | 10 PLAIN AXIALLY THROUGH BODY FIRST END |
| Mounting Hole Nominal Diameter | 0.375 INCHES AXIALLY THROUGH BODY FIRST END IN |
| Teeth Type | SINGLE HELIX |
| Hardness Rating | 48.5 ROCKWELL C MINIMUM AND 59.2 ROCKWELL C MAXIMUM OVERALL |
| Style Designator | HUBLESS |
| Material Document and Classification | 66 FED STD SINGLE MATERIAL RESPONSE AND AISI/SAE 1040 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Pitch Diameter | 24.0300 INCHES NOMINAL IN |
| Tooth Form | STANDARD |
| Nominal Outside Diameter | 24.278 INCHES IN |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL COMP 1040 OVERALL |
| Counterbore Nominal Depth | 0.313 INCHES COUNTERBORE FIRST END IN |
| Attachment Method | MOUNTING HOLE |
| Face Nominal Width | 1.250 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 |
|---|---|
| 6B9537 PRIMARY | Caterpillar Inc Div Caterpillar Defense (USA) |
| Reference | Meaning |
|---|---|
| IPD6B9537 | 5/9 Secondary reference Industrial Parts Depot, Llc Dba Ipd |
NSN 3020-00-423-9985 is a Gear,helical, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
NSN 3020-00-423-9985 has 1 manufacturer part number on file: 6B9537 (Caterpillar Inc Div Caterpillar Defense).
Key specifications for 6B9537: Bore Nominal Diameter: 21.226 INCHES COUNTERBORE FIRST END IN; Helix Angle: 15.4083 DEGREES; Teeth Quantity: 139; Body Style: PLAIN, SOLID. 21 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.