The Gear,internal, cataloged under National Stock Number 3020-01-416-3312, 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 Naval Sea Systems Command. Government technical data includes 24 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 3020-01-416-3312 |
| Primary Part Number | 6406709-78 |
| Item Name | Gear,internal |
| FSC / FSG | 3020 / 30 — Gears, Pulleys, Sprockets, and Transmission Chain |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Bore Nominal Diameter | 1.503 INCHES BOTH ENDS IN |
| Teeth Quantity | 42 |
| Second Step Nominal Diameter | 3.500 INCHES FIRST END IN |
| Body Style | PLAIN, SOLID |
| Bore Style | STRAIGHT SPLINE BETWEEN BODY AND FLANGE |
| Nominal Distance Between Body Face and Protruding Hub End | 1.065 INCHES FIRST END IN |
| First Step Nominal Length | 0.219 INCHES FIRST END IN |
| Teeth Type | SPUR |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Overall Length | 3.940 INCHES IN |
| Second Step Nominal Length | 0.846 INCHES FIRST END IN |
| Style Designator | SOLID BACK RING, PROTRUDING HUB |
| Material Document and Classification | MIL-S-5000 COND C MIL STD SINGLE MATERIAL RESPONSE OVERALL |
| Pitch Diameter | 4.2000 INCHES NOMINAL IN |
| Tooth Form | STUB |
| First Step Nominal Diameter | 4.499 INCHES FIRST END IN |
| Hub Style Designator | 2 STEPS FIRST END |
| Spline Quantity | 9 BOTH ENDS |
| End Nominal Length | 1.065 INCHES FIRST END IN |
| Nominal Outside Diameter | 5.343 INCHES IN |
| End Nominal Diameter | 3.500 INCHES FIRST END IN |
| Pressure Angle | 20.0000 DEGREES |
| Material | STEEL OVERALL |
| Face Nominal Width | 0.875 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 |
|---|---|
| 6406709-78 PRIMARY | Naval Sea Systems Command (USA) |
| 211060605 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 801-6406709-78 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 6406709 | D/9 Drawing number reference only Naval Sea Systems Command |
NSN 3020-01-416-3312 is a Gear,internal, manufactured by Naval Sea Systems Command, classified under FSC 3020, Gears, Pulleys, Sprockets, and Transmission Chain. Status: active.
NSN 3020-01-416-3312 has 2 manufacturer part numbers on file: 6406709-78 (Naval Sea Systems Command), 211060605 (Naval Sea Systems Command).
5 possible matches (shared part number, not a government interchangeability claim): 4820-01-416-6864, 3020-01-421-5277, 4820-01-422-2300. Verify interchangeability with system specifications before substitution.
Key specifications for 6406709-78: Bore Nominal Diameter: 1.503 INCHES BOTH ENDS IN; Teeth Quantity: 42; Second Step Nominal Diameter: 3.500 INCHES FIRST END IN; Body Style: PLAIN, SOLID. 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.