PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

2N491BTransistor

Osi Optoelectronics, Inc Dba Semicoa · NSN 5961-00-766-2947 · FSC 5961 · No Item Name Available
Verified by PartsTable
NSN 5961-00-766-2947 — this item is cataloged by the U.S. Government under National Stock Number 5961-00-766-2947. Primary manufacturer part number: 2N491B.
Features
  • Transistor — FSC 5961
  • Terminal Length: 1.500 INCHES MINIMUM IN
  • Terminal Type and Quantity: 3 UNINSULATED WIRE LEAD
  • Overall Diameter: 0.370 INCHES MAXIMUM IN
  • Mounting Method: TERMINAL
  • Power Rating Per Characteristic: 450.0 MILLIWATTS MAXIMUM TOTAL POWER DISSIPATION
  • Features Provided: HERMETICALLY SEALED CASE
  • Semiconductor Material: SILICON
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Transistor, cataloged under National Stock Number 5961-00-766-2947, is classified within Federal Supply Class 5961 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is Osi Optoelectronics, Inc Dba Semicoa. Government technical data includes 11 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 12 commercial cross-references from 9 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5961-00-766-2947
Primary Part Number2N491B
Item NameTransistor
FSC / FSG5961 / 59 — No Item Name Available
ManufacturerOsi Optoelectronics, Inc Dba Semicoa
StatusCANCELLED
Terminal Length1.500 INCHES MINIMUM IN
Terminal Type and Quantity3 UNINSULATED WIRE LEAD
Overall Diameter0.370 INCHES MAXIMUM IN
Mounting MethodTERMINAL
Power Rating Per Characteristic450.0 MILLIWATTS MAXIMUM TOTAL POWER DISSIPATION
Features ProvidedHERMETICALLY SEALED CASE
Semiconductor MaterialSILICON
Terminal Circle Diameter0.200 INCHES NOMINAL IN
Specification/standard Data80131-RELEASE3648 PROFESSIONAL/INDUSTRIAL ASSOCIATION SPECIFICATION
Current Rating Per Characteristic6.00 MICROAMPERES MAXIMUM PEAK POINT CURRENT
Internal ConfigurationJUNCTION CONTACT
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 4
5961-00-239-9589 INTERCHANGEABLE
Transistor
5961-00-777-6536 INTERCHANGEABLE
Transistor
5961-00-913-2863 INTERCHANGEABLE
Transistor
5961-00-964-4469 INTERCHANGEABLE
Transistor
Cross-Reference Index
Part NumberManufacturer
2N491B Osi Optoelectronics, Inc Dba Semicoa (USA)
RELEASE4064 Electronic Industries Association
2N491B Electronic Industries Association
2N491B Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
2N2419B Electronic Industries Association
KS19777L2 Lucent Technologies Inc Dba Federal Marketing Group (USA)
RELEASE3648 Electronic Industries Association
2N2419B General Electric Co Semi-Conductor Products Dept Power Components Opn (USA)
2N491B Csr Industries Inc (USA)
2N491B General Electric Company (USA)
2N491B Solid State Devices, Inc (USA)
2N491B Texas Instruments Incorporated (USA)
Related Parts
5961-00-239-9589INTERCHANGEABLE
TRANSISTOR
5961-00-777-6536INTERCHANGEABLE
TRANSISTOR
5961-00-913-2863INTERCHANGEABLE
TRANSISTOR
5961-00-964-4469INTERCHANGEABLE
TRANSISTOR

Frequently Asked Questions

What is NSN 5961-00-766-2947?

NSN 5961-00-766-2947 is a Transistor, manufactured by Osi Optoelectronics, Inc Dba Semicoa, classified under FSC 5961 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5961-00-766-2947?

NSN 5961-00-766-2947 has 12 cross-referenced part numbers: 2N491B (Osi Optoelectronics, Inc Dba Semicoa), RELEASE4064 (Electronic Industries Association), 2N491B (Electronic Industries Association), 2N491B (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 2N2419B (Electronic Industries Association) and 7 more.

What NSN replaces 5961-00-766-2947?

There are 4 known substitutes for 5961-00-766-2947: 5961-00-239-9589, 5961-00-777-6536, 5961-00-913-2863 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 2N491B?

Key specifications for 2N491B: Terminal Length: 1.500 INCHES MINIMUM IN; Overall Length: 0.260 INCHES MAXIMUM IN; Terminal Type and Quantity: 3 UNINSULATED WIRE LEAD; Special Features: JUNCTION PATTERN ARRANGEMENT: PNP. 13 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5961-00-766-2947 still in active supply?

NSN 5961-00-766-2947 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com