PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

1235962Window,optical Instrument

Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier · NSN 1240-00-171-4177 · FSC 1240 · No Item Name Available
Verified by PartsTable
NSN 1240-00-171-4177 — this item is cataloged by the U.S. Government under National Stock Number 1240-00-171-4177. Primary manufacturer part number: 1235962.
Features
  • Window,optical Instrument — FSC 1240
  • Polished Periphery: NOT PROVIDED
  • Length: 349.000 MILLIMETERS MINIMUM AND 350.000 MILLIMETERS MAXIMUM MM
  • Reflection Reducing Surface: ONE
  • FSC Application Data: TELESCOPE MK 102 MOD 3
  • Material Document and Classification: JAN-G-174, TYPE 517-645, GRADE C MIL SPEC SINGLE MATERIAL RESPONSE LOCATION NOT OTHERWISE SPECIFIED
  • Material: GLASS OPTICAL LOCATION NOT OTHERWISE SPECIFIED
  • Bevel Depth: 2.000 MILLIMETERS NOMINAL MM
Applications
  • Applications requiring Glass Optical Location Not Otherwise Specified construction
General Description

The Window,optical Instrument, cataloged under National Stock Number 1240-00-171-4177, is classified within Federal Supply Class 1240 (No Item Name Available) of the Fire Control Equipment group. The primary manufacturer of record is Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier. Government technical data includes 12 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN1240-00-171-4177
Primary Part Number1235962
Item NameWindow,optical Instrument
FSC / FSG1240 / 12 — No Item Name Available
ManufacturerNavair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier
StatusACTIVE
Polished PeripheryNOT PROVIDED
Length349.000 MILLIMETERS MINIMUM AND 350.000 MILLIMETERS MAXIMUM MM
Reflection Reducing SurfaceONE
FSC Application DataTELESCOPE MK 102 MOD 3
Material Document and ClassificationJAN-G-174, TYPE 517-645, GRADE C MIL SPEC SINGLE MATERIAL RESPONSE LOCATION NOT OTHERWISE SPECIFIED
MaterialGLASS OPTICAL LOCATION NOT OTHERWISE SPECIFIED
Bevel Depth2.000 MILLIMETERS NOMINAL MM
Bevel Angle in Deg45.000 NOMINAL
Width287.000 MILLIMETERS MINIMUM AND 288.000 MILLIMETERS MAXIMUM MM
Refraction Index1.5170 NOMINAL
Dispersion64.5 ANGSTROMS NOMINAL
Thickness18.800 MILLIMETERS MINIMUM AND 19.200 MILLIMETERS MAXIMUM MM
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 9
3110-00-100-03320042898-7 INTERCHANGEABLE
Cup,tapered Roller Bearing
New Holland Construction
5330-00-176-4123141A77 INTERCHANGEABLE
Gasket
Cummins Power Generation Inc.
5985-00-671-8324712260-23 INTERCHANGEABLE
Dummy Load,electrical
Raytheon Company Div Rmd Strategic
3110-00-975-2132 INTERCHANGEABLE
Ring,bearing,inner
5305-01-104-274530091 INTERCHANGEABLE
Screw,cap,hexagon Head
Leroi International Inc Dba Compair Leroi
5935-01-124-2461C8804-6-1 INTERCHANGEABLE
Connector,plug,electrical
Lockheed Martin Corporation Div Lockheed Martin Aeronautics Company
5950-01-149-923230091 INTERCHANGEABLE
Transformer,power
Transistor Devices Inc Div Astrodyne Tdi High Power Business Unit
4820-01-242-147127301 PC6 3IN INTERCHANGEABLE
Disk,valve
Crane Co Div Valve Div
4820-01-242-297027301 PC9 3IN INTERCHANGEABLE
Stem,fluid Valve
Crane Co Div Valve Div
Cross-Reference Index
Part NumberManufacturer
1235962 PRIMARY Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier (USA)
30091 Optical Technology Devices Inc (USA)
Related Parts
3110-00-100-0332INTERCHANGEABLE
CUP,TAPERED ROLLER BEARING
0042898-7
5330-00-176-4123INTERCHANGEABLE
GASKET
141A77
5985-00-671-8324INTERCHANGEABLE
DUMMY LOAD,ELECTRICAL
712260-23
3110-00-975-2132INTERCHANGEABLE
RING,BEARING,INNER
5305-01-104-2745INTERCHANGEABLE
SCREW,CAP,HEXAGON HEAD
30091
5935-01-124-2461INTERCHANGEABLE
CONNECTOR,PLUG,ELECTRICAL
C8804-6-1
5950-01-149-9232INTERCHANGEABLE
TRANSFORMER,POWER
30091
4820-01-242-1471INTERCHANGEABLE
DISK,VALVE
27301 PC6 3IN
4820-01-242-2970INTERCHANGEABLE
STEM,FLUID VALVE
27301 PC9 3IN

Frequently Asked Questions

What is NSN 1240-00-171-4177?

NSN 1240-00-171-4177 is a Window,optical Instrument, manufactured by Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier, classified under FSC 1240 (No Item Name Available). Status: active.

What are the part numbers for NSN 1240-00-171-4177?

NSN 1240-00-171-4177 has 2 cross-referenced part numbers: 1235962 (Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier), 30091 (Optical Technology Devices Inc).

What NSN replaces 1240-00-171-4177?

There are 9 known substitutes for 1240-00-171-4177: 3110-00-100-0332, 5330-00-176-4123, 5985-00-671-8324 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 1235962?

Key specifications for 1235962: Polished Periphery: NOT PROVIDED; Length: 349.000 MILLIMETERS MINIMUM AND 350.000 MILLIMETERS MAXIMUM MM; Reflection Reducing Surface: ONE; Special Features: FOUR ROUNDED CORNERS 26.5 MM PLUS 1.0,MINUS 0.0 (1.0433 IN.) RADIUS MM. 13 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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