The Gear,helical, cataloged under National Stock Number 3020-00-438-6950, is classified within Federal Supply Class 3020 (Gears, Pulleys, Sprockets, and Transmission Chain) of the Mechanical Power Transmission Equipment group. Government technical data includes 26 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3020-00-438-6950 |
| Item Name | Gear,helical |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Status | ACTIVE |
| Bore Nominal Diameter | 0.250 INCHES BOTH ENDS IN |
| Helix Angle | 45.0000 DEGREES |
| Hub Nominal Diameter | 0.500 INCHES FIRST END IN |
| Teeth Quantity | 20 |
| Body Style | PLAIN, SOLID |
| Tooth Direction | LEFT |
| Bore Style | PLAIN BOTH ENDS |
| Mounting Hole Type and Quantity | 1 PLAIN AND 1 THREADED TRANSVERSELY THROUGH HUB FIRST END |
| Nominal Distance Between Body Face and Protruding Hub End | 0.253 INCHES FIRST END IN |
| Mounting Hole Nominal Diameter | 0.047 INCHES TRANSVERSELY THROUGH HUB FIRST END IN |
| Teeth Type | SINGLE HELIX |
| Nominal Overall Length | 0.440 INCHES IN |
| Style Designator | PROTRUDING HUB |
| Material Document and Classification | QQ-S-764,COND A FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Pitch Diameter | 0.5892 INCHES NOMINAL IN |
| Tooth Form | STANDARD |
| Hub Style Designator | PLAIN FIRST END |
| Mounting Hole Nominal Thread Size | 0.138 INCHES TRANSVERSELY THROUGH HUB FIRST END IN |
| Nominal Outside Diameter | 0.630 INCHES IN |
| Mounting Hole Thread Quantity Per Inch | 32 TRANSVERSELY THROUGH HUB FIRST END |
| Surface Treatment | PASSIVATE OVERALL |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL COMP 303 OVERALL |
| Mounting Hole Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) TRANSVERSELY THROUGH HUB FIRST END |
| Attachment Method | MOUNTING HOLE |
| Face Nominal Width | 0.187 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 |
| Reference | Meaning |
|---|---|
| 334-686 | 3/2 Design control — primary reference U.S. Government activity |
NSN 3020-00-438-6950 is a Gear,helical, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
Key specifications for 3020-00-438-6950: Bore Nominal Diameter: 0.250 INCHES BOTH ENDS IN; Helix Angle: 45.0000 DEGREES; Hub Nominal Diameter: 0.500 INCHES FIRST END IN; Teeth Quantity: 20. 26 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.