PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MILG2857Window,observation

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 9340-00-400-2958 · FSC 9340 · No Item Name Available
Verified by PartsTable
NSN 9340-00-400-2958 — this item is cataloged by the U.S. Government under National Stock Number 9340-00-400-2958. Primary manufacturer part number: MILG2857.
Features
  • Window,observation — FSC 9340
  • Environmental Protection: WEATHER RESISTANT
  • Surface Finish: POLISHED
  • Edge Type: FLAT FINISH
  • Material: GLASS
  • Hardness Rating: 1800.0 MOHS NOMINAL
  • Style Designator: SQUARE CORNERS
  • Reference Number Differentiating Characteristics: AS DIFFERENTIATED BY SYMBOL 12-17
Applications
  • Applications requiring Glass construction
General Description

The Window,observation, cataloged under National Stock Number 9340-00-400-2958, is classified within Federal Supply Class 9340 (No Item Name Available) of the Nonmetallic Fabricated Materials group. The primary manufacturer of record is Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 12 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 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
NSN9340-00-400-2958
Primary Part NumberMILG2857
Item NameWindow,observation
FSC / FSG9340 / 93 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Environmental ProtectionWEATHER RESISTANT
Surface FinishPOLISHED
Edge TypeFLAT FINISH
MaterialGLASS
Hardness Rating1800.0 MOHS NOMINAL
Style DesignatorSQUARE CORNERS
Reference Number Differentiating CharacteristicsAS DIFFERENTIATED BY SYMBOL 12-17
Material Document and ClassificationDD-G-451,TYPE 1 FED SPEC SINGLE MATERIAL RESPONSE
Material TransparencyCLEAR
Temp at Maximum Operating Pressure150.0 FAHRENHEIT DEGF
Ply Quantity4
Overall Thickness1.740 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
9340-00-054-9084KS-8455 PC 5 INTERCHANGEABLE
Glass,laminated
Cornell-Carr Co., Inc.
9340-00-211-6055CC-1138-123 INTERCHANGEABLE
Glass,laminated
Cornell-Carr Co., Inc.
9340-00-214-8778CC-1138-124 INTERCHANGEABLE
Glass,laminated
Cornell-Carr Co., Inc.
9340-00-369-9966 INTERCHANGEABLE
Window,observation
9340-00-369-9967 INTERCHANGEABLE
Window,observation
9340-00-400-2933 INTERCHANGEABLE
Window,observation
9340-00-400-2957 INTERCHANGEABLE
Window,observation
9340-00-468-141588464 INTERCHANGEABLE
Window,observation
Kaydon Custom Filtration Corporation
9340-00-468-141819D5003P3 INTERCHANGEABLE
Window,observation
Westinghouse Electric Corp
5355-00-582-7370B311-285 INTERCHANGEABLE
Window,dial
Northrop Grumman Systems Corp Dba Northrop Grumman Systems Corp
Cross-Reference Index
Part NumberManufacturer
MILG2857 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
KS11678A Bae Systems Information and Electronic Systems Integration I Dba Es Marine Systems (USA)
KS11678ASYM12 17 Bae Systems Information and Electronic Systems Integration I Dba Es Marine Systems (USA)
Related Parts
9340-00-054-9084INTERCHANGEABLE
GLASS,LAMINATED
KS-8455 PC 5
9340-00-211-6055INTERCHANGEABLE
GLASS,LAMINATED
CC-1138-123
9340-00-214-8778INTERCHANGEABLE
GLASS,LAMINATED
CC-1138-124
9340-00-369-9966INTERCHANGEABLE
WINDOW,OBSERVATION
9340-00-369-9967INTERCHANGEABLE
WINDOW,OBSERVATION
9340-00-400-2933INTERCHANGEABLE
WINDOW,OBSERVATION
9340-00-400-2957INTERCHANGEABLE
WINDOW,OBSERVATION
9340-00-468-1415INTERCHANGEABLE
WINDOW,OBSERVATION
88464
9340-00-468-1418INTERCHANGEABLE
WINDOW,OBSERVATION
19D5003P3
5355-00-582-7370INTERCHANGEABLE
WINDOW,DIAL
B311-285
9340-00-764-4399INTERCHANGEABLE
GLASS,LAMINATED
9340-01-396-2126INTERCHANGEABLE
WINDOW,OBSERVATION
5388303

Frequently Asked Questions

What is NSN 9340-00-400-2958?

NSN 9340-00-400-2958 is a Window,observation, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 9340 (No Item Name Available). Status: active.

What are the part numbers for NSN 9340-00-400-2958?

NSN 9340-00-400-2958 has 3 cross-referenced part numbers: MILG2857 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), KS11678A (Bae Systems Information and Electronic Systems Integration I Dba Es Marine Systems), KS11678ASYM12 17 (Bae Systems Information and Electronic Systems Integration I Dba Es Marine Systems).

What NSN replaces 9340-00-400-2958?

There are 12 known substitutes for 9340-00-400-2958: 9340-00-054-9084, 9340-00-211-6055, 9340-00-214-8778 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MILG2857?

Key specifications for MILG2857: Environmental Protection: WEATHER RESISTANT; Surface Finish: POLISHED; Overall Length: 29.375 INCHES NOMINAL IN; Edge Type: FLAT FINISH. 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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