PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

6939Gear,internal

Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic · NSN 3020-00-374-1029 · FSC 3020 · No Item Name Available
Verified by PartsTable
NSN 3020-00-374-1029 — this item is cataloged by the U.S. Government under National Stock Number 3020-00-374-1029. Primary manufacturer part number: 6939.
Features
  • Gear,internal — FSC 3020
  • Nominal Outside Diameter: 8.498 INCHES IN
  • Teeth Quantity: 42
  • Mounting Hole Type and Quantity: 6 PLAIN AXIALLY THROUGH BODY FIRST END
  • Teeth Type: SPUR
  • Tooth Form: STANDARD
  • Material: IRON CAST OVERALL
  • Body Style: PLAIN, SOLID
Applications
  • Power transmission and speed reduction
  • Rotary motion transfer
  • Torque multiplication
  • Applications requiring Iron Cast Overall construction
General Description

The Gear,internal, cataloged under National Stock Number 3020-00-374-1029, is classified within Federal Supply Class 3020 (No Item Name Available) of the Mechanical Power Transmission Equipment group. The primary manufacturer of record is Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic. Government technical data includes 14 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN3020-00-374-1029
Primary Part Number6939
Item NameGear,internal
FSC / FSG3020 / 30 — No Item Name Available
ManufacturerTwin Disc, Incorporated Dba Twin Disc Mid-Atlantic
StatusACTIVE
Nominal Outside Diameter8.498 INCHES IN
Teeth Quantity42
Mounting Hole Type and Quantity6 PLAIN AXIALLY THROUGH BODY FIRST END
Teeth TypeSPUR
Tooth FormSTANDARD
MaterialIRON CAST OVERALL
Body StylePLAIN, SOLID
Pressure Angle20.0000 DEGREES
Bolt Hole Circle Nominal Diameter0.875 INCHES AXIALLY THROUGH BODY FIRST END IN
Attachment MethodMOUNTING HOLE
Pitch Diameter7.0000 INCHES NOMINAL IN
Mounting Hole Nominal Diameter0.328 INCHES AXIALLY THROUGH BODY FIRST END IN
Nominal Overall Length0.625 INCHES IN
Style DesignatorPLAIN RING
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
6510-00-116-13116939G INTERCHANGEABLE
Sponge,surgical
Cardinal Health 200, Llc
2910-00-185-7635293-58 INTERCHANGEABLE
Stop,reed Valve
Clinton Engines Corp
5133-00-228-1332 INTERCHANGEABLE
Drill,twist
5340-00-246-74026939 INTERCHANGEABLE
Clevis,rod End
Lockheed Martin Corporation Div Lockheed Martin Aeronautics Company
2940-00-308-84398678327 INTERCHANGEABLE
Filter Element,intake Air Cleane
U S Army Tank Automotive Command Amsta-Im-Mm
5930-00-356-82126939 INTERCHANGEABLE
Switch,toggle
Clayton Manufacturing Company
3439-00-421-8737 INTERCHANGEABLE
Desoldering Tool,electric
5960-00-617-6178 INTERCHANGEABLE
Electron Tube
5960-00-729-2463 INTERCHANGEABLE
Electron Tube
5342-00-784-3441 INTERCHANGEABLE
Bracket,pump
Cross-Reference Index
Part NumberManufacturer
29358 Davey Compressor Co Div of Keco Industries Inc (USA)
30859 Drs Environmental Systems Inc (USA)
30859 Davey Compressor Co Div of Keco Industries Inc (USA)
6939 PRIMARY Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA)
X2113 Blaw Knox Corp Blaw-Knox Equipment Div (USA)
29358 Drs Environmental Systems Inc (USA)
30859 Hdt Expeditionary Systems Inc (USA)
29358 Hdt Expeditionary Systems Inc (USA)
Related Parts
6510-00-116-1311INTERCHANGEABLE
SPONGE,SURGICAL
6939G
2910-00-185-7635INTERCHANGEABLE
STOP,REED VALVE
293-58
5133-00-228-1332INTERCHANGEABLE
DRILL,TWIST
5340-00-246-7402INTERCHANGEABLE
CLEVIS,ROD END
6939
2940-00-308-8439INTERCHANGEABLE
FILTER ELEMENT,INTAKE AIR CLEANE
8678327
5930-00-356-8212INTERCHANGEABLE
SWITCH,TOGGLE
6939
3439-00-421-8737INTERCHANGEABLE
DESOLDERING TOOL,ELECTRIC
5960-00-617-6178INTERCHANGEABLE
ELECTRON TUBE
5960-00-729-2463INTERCHANGEABLE
ELECTRON TUBE
5342-00-784-3441INTERCHANGEABLE
BRACKET,PUMP
1650-01-031-9037INTERCHANGEABLE
ADJUSTER ASSEMBLY,DRIVE ASSEMBLY
29358
5310-01-155-3445INTERCHANGEABLE
WASHER,FLAT
2BA553

Frequently Asked Questions

What is NSN 3020-00-374-1029?

NSN 3020-00-374-1029 is a Gear,internal, manufactured by Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic, classified under FSC 3020 (No Item Name Available). Status: active.

What are the part numbers for NSN 3020-00-374-1029?

NSN 3020-00-374-1029 has 8 cross-referenced part numbers: 29358 (Davey Compressor Co Div of Keco Industries Inc), 30859 (Drs Environmental Systems Inc), 30859 (Davey Compressor Co Div of Keco Industries Inc), 6939 (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic), X2113 (Blaw Knox Corp Blaw-Knox Equipment Div) and 3 more.

What NSN replaces 3020-00-374-1029?

There are 12 known substitutes for 3020-00-374-1029: 6510-00-116-1311, 2910-00-185-7635, 5133-00-228-1332 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 6939?

Key specifications for 6939: Nominal Outside Diameter: 8.498 INCHES IN; Teeth Quantity: 42; Special Features: MTG HOLES 60 DEG APART; Mounting Hole Type and Quantity: 6 PLAIN AXIALLY THROUGH BODY FIRST END. 15 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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