The Gear,helical, cataloged under National Stock Number 3020-00-657-8527, 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 U S Army Tank Automotive Command Amsta-Im-Mm. Government technical data includes 24 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 3020-00-657-8527 |
| Primary Part Number | 6578527 |
| Item Name | Gear,helical |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Manufacturer | U S Army Tank Automotive Command Amsta-Im-Mm |
| Status | ACTIVE |
| Bore Nominal Diameter | 3.876 INCHES BOTH ENDS IN |
| Helix Angle | 24.7839 DEGREES |
| Hub Nominal Diameter | 6.688 INCHES FIRST END IN |
| Hub Nominal Diameter | 6.688 INCHES SECOND END IN |
| Teeth Quantity | 42 |
| Body Style | WEBBED, SOLID |
| Tooth Direction | RIGHT |
| Bore Style | PLAIN BOTH ENDS |
| Mounting Hole Type and Quantity | 6 PLAIN AXIALLY THROUGH HUB FIRST END |
| Mounting Hole Nominal Diameter | 0.562 INCHES AXIALLY THROUGH HUB FIRST END IN |
| Teeth Type | SINGLE HELIX |
| Hardness Rating | 58.0 ROCKWELL C MINIMUM AND 65.0 ROCKWELL C MAXIMUM OVERALL |
| Style Designator | FLUSH HUB |
| Material Document and Classification | ED STD 66,AISI/SAE 8620H FED STD 5TH MATERIAL RESPONSE OVERALL |
| Pitch Diameter | 9.2520 INCHES NOMINAL IN |
| Tooth Form | STANDARD |
| Hub Style Designator | PLAIN BOTH ENDS |
| Nominal Outside Diameter | 9.650 INCHES IN |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL COMP 8620H OVERALL |
| Bolt Hole Circle Nominal Diameter | 4.750 INCHES AXIALLY THROUGH HUB FIRST END IN |
| Counterbore Nominal Depth | 0.625 INCHES BOTH ENDS IN |
| Attachment Method | MOUNTING HOLE |
| Face Nominal Width | 1.750 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 |
|---|---|
| 6578527 PRIMARY | U S Army Tank Automotive Command Amsta-Im-Mm (USA) |
| Reference | Meaning |
|---|---|
| 0E311 | 5/9 Secondary reference U.S. Government activity |
NSN 3020-00-657-8527 is a Gear,helical, manufactured by U S Army Tank Automotive Command Amsta-Im-Mm, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
NSN 3020-00-657-8527 has 1 manufacturer part number on file: 6578527 (U S Army Tank Automotive Command Amsta-Im-Mm).
Key specifications for 6578527: Bore Nominal Diameter: 3.876 INCHES BOTH ENDS IN; Helix Angle: 24.7839 DEGREES; Hub Nominal Diameter: 6.688 INCHES FIRST END IN; Hub Nominal Diameter: 6.688 INCHES SECOND END IN. 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.