PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

34521Thumbwheel

Safe Flight Instrument, Llc · NSN 4920-01-109-8540 · FSC 4920 · No Item Name Available
Verified by PartsTable
NSN 4920-01-109-8540 — this item is cataloged by the U.S. Government under National Stock Number 4920-01-109-8540. Primary manufacturer part number: 34521.
Features
  • Thumbwheel — FSC 4920
  • General Characteristics Item Description: MATL: 303 STAINLESS STEEL; FINISH: PASSIVATE QQ-P-35; O/A DIM: 0.750 IN. DIA.,0.190 IN. H. IN
  • 1 verified cross-reference
  • Primary manufacturer: Safe Flight Instrument, Llc
Applications
  • Maintenance depot operations
  • Field repair and servicing
  • Vehicle maintenance facilities
General Description

The Thumbwheel, cataloged under National Stock Number 4920-01-109-8540, is classified within Federal Supply Class 4920 (No Item Name Available) of the Maintenance and Repair Shop Equipment group. The primary manufacturer of record is Safe Flight Instrument, Llc. Government technical data includes 1 verified specification, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4920-01-109-8540
Primary Part Number34521
Item NameThumbwheel
FSC / FSG4920 / 49 — No Item Name Available
ManufacturerSafe Flight Instrument, Llc
StatusACTIVE
General Characteristics Item DescriptionMATL: 303 STAINLESS STEEL; FINISH: PASSIVATE QQ-P-35; O/A DIM: 0.750 IN. DIA.,0.190 IN. H. IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
5310-00-171-35285B5961 INTERCHANGEABLE
Washer,flat
Caterpillar Inc Div Caterpillar Defense
3810-00-830-77581017021 INTERCHANGEABLE
Seal Body Panel
Fwd Seagrave Holdings Lp
5995-01-468-805234521 INTERCHANGEABLE
Cable Assembly,radio Frequency
Phoenix Logistics, Llc
5133-01-672-644334521 INTERCHANGEABLE
Drill,twist
Viking Drill & Tool, Inc.
Cross-Reference Index
Part NumberManufacturer
34521 PRIMARY Safe Flight Instrument, Llc (USA)
Related Parts
5310-00-171-3528INTERCHANGEABLE
WASHER,FLAT
5B5961
3810-00-830-7758INTERCHANGEABLE
SEAL BODY PANEL
1017021
5995-01-468-8052INTERCHANGEABLE
CABLE ASSEMBLY,RADIO FREQUENCY
34521
5133-01-672-6443INTERCHANGEABLE
DRILL,TWIST
34521

Frequently Asked Questions

What is NSN 4920-01-109-8540?

NSN 4920-01-109-8540 is a Thumbwheel, manufactured by Safe Flight Instrument, Llc, classified under FSC 4920 (No Item Name Available). Status: active.

What are the part numbers for NSN 4920-01-109-8540?

NSN 4920-01-109-8540 has 1 cross-referenced part number: 34521 (Safe Flight Instrument, Llc).

What NSN replaces 4920-01-109-8540?

There are 4 known substitutes for 4920-01-109-8540: 5310-00-171-3528, 3810-00-830-7758, 5995-01-468-8052 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 34521?

Key specifications for 34521: General Characteristics Item Description: MATL: 303 STAINLESS STEEL; FINISH: PASSIVATE QQ-P-35; O/A DIM: 0.750 IN. DIA.,0.190 IN. H. IN; End Item Identification: A10A ACFT AGE.. 2 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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