PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

S51Indicator,sight,liquid

Eaton Aerospace Llc Div Fluid and Electrical Distribution Division · NSN 6680-00-905-2664 · FSC 6680 · No Item Name Available
Verified by PartsTable
NSN 6680-00-905-2664 — this item is cataloged by the U.S. Government under National Stock Number 6680-00-905-2664. Primary manufacturer part number: S51.
Features
  • Indicator,sight,liquid — FSC 6680
  • Width Across Flats: 1.630 INCHES NOMINAL IN
  • Style Designator: BULLS EYE
  • End Connection Type: UNABLE TO DECODE
  • Thread Series Designator: UNABLE TO DECODE
  • Maximum Working Pressure: 690.0 POUNDS PER SQUARE INCH (PSI) LBS
  • Thread Class: UNABLE TO DECODE
  • Data Furnishing Method: CLEAR WINDOW
Applications
  • Applications requiring Aluminum Alloy construction
General Description

The Indicator,sight,liquid, cataloged under National Stock Number 6680-00-905-2664, is classified within Federal Supply Class 6680 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Eaton Aerospace Llc Div Fluid and Electrical Distribution Division. Government technical data includes 17 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 5 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN6680-00-905-2664
Primary Part NumberS51
Item NameIndicator,sight,liquid
FSC / FSG6680 / 66 — No Item Name Available
ManufacturerEaton Aerospace Llc Div Fluid and Electrical Distribution Division
StatusCANCELLED
Width Across Flats1.630 INCHES NOMINAL IN
Style DesignatorBULLS EYE
End Connection TypeUNABLE TO DECODE
Thread Series DesignatorUNABLE TO DECODE
Maximum Working Pressure690.0 POUNDS PER SQUARE INCH (PSI) LBS
Thread ClassUNABLE TO DECODE
Data Furnishing MethodCLEAR WINDOW
Nominal Thread SizeUNABLE TO DECODE
Thread DirectionUNABLE TO DECODE
Features ProvidedREFLECTOR
Media for Which DesignedOIL
Sight Diameter1.000 INCHES NOMINAL IN
Maximum Temp Rating200.0 FAHRENHEIT DEGF
Surface TreatmentANODIZE
MaterialALUMINUM ALLOY
Thread Quantity Per InchUNABLE TO DECODE
Furnished DataLIQUID LEVEL
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 9
3460-00-189-9120 INTERCHANGEABLE
Holder,cutting Tool
5120-00-287-2503 INTERCHANGEABLE
Screwdriver,flat Tip
4820-00-425-958735711 INTERCHANGEABLE
Valve,plug
Aeroil Products Co Inc
3455-00-517-59671743-0312 INTERCHANGEABLE
Cutter,milling,end
New York Twist Drill Inc
5340-00-616-4697S51 INTERCHANGEABLE
Plunger,quick Release
Hutchinson Aerospace & Industry, Inc. Dba Vlier Div Vlier
5950-00-648-1405288-1103-00 INTERCHANGEABLE
Core,electromagnetic Component
Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems
6625-01-250-3837S51 INTERCHANGEABLE
Sampling Head
Tektronix, Inc.
3920-01-253-8867S-5-1 INTERCHANGEABLE
Truck,hand
Rol-Away Truck Manufacturing Company, Inc. Dba Rol-Away Truck Manufacturing Co Inc
6680-01-514-0321S-51 INTERCHANGEABLE
Indicator,sight,liquid
Bell Textron Inc
Cross-Reference Index
Part NumberManufacturer
CS2009-157140 Ldi Industries, Inc. Dba Ldi Industries Inc (USA)
CX15920-16R Ldi Industries, Inc. Dba Ldi Industries Inc (USA)
S51 PRIMARY Eaton Aerospace Llc Div Fluid and Electrical Distribution Division (USA)
51 Eaton Aerospace Llc Div Fluid and Electrical Distribution Division (USA)
S51 Satair A/s (DNK)
Related Parts
3460-00-189-9120INTERCHANGEABLE
HOLDER,CUTTING TOOL
5120-00-287-2503INTERCHANGEABLE
SCREWDRIVER,FLAT TIP
4820-00-425-9587INTERCHANGEABLE
VALVE,PLUG
35711
3455-00-517-5967INTERCHANGEABLE
CUTTER,MILLING,END
1743-0312
5340-00-616-4697INTERCHANGEABLE
PLUNGER,QUICK RELEASE
S51
5950-00-648-1405INTERCHANGEABLE
CORE,ELECTROMAGNETIC COMPONENT
288-1103-00
6625-01-250-3837INTERCHANGEABLE
SAMPLING HEAD
S51
3920-01-253-8867INTERCHANGEABLE
TRUCK,HAND
S-5-1
6680-01-514-0321INTERCHANGEABLE
INDICATOR,SIGHT,LIQUID
S-51

Frequently Asked Questions

What is NSN 6680-00-905-2664?

NSN 6680-00-905-2664 is a Indicator,sight,liquid, manufactured by Eaton Aerospace Llc Div Fluid and Electrical Distribution Division, classified under FSC 6680 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 6680-00-905-2664?

NSN 6680-00-905-2664 has 5 cross-referenced part numbers: CS2009-157140 (Ldi Industries, Inc. Dba Ldi Industries Inc), CX15920-16R (Ldi Industries, Inc. Dba Ldi Industries Inc), S51 (Eaton Aerospace Llc Div Fluid and Electrical Distribution Division), 51 (Eaton Aerospace Llc Div Fluid and Electrical Distribution Division), S51 (Satair A/s).

What NSN replaces 6680-00-905-2664?

There are 9 known substitutes for 6680-00-905-2664: 3460-00-189-9120, 5120-00-287-2503, 4820-00-425-9587 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of S51?

Key specifications for S51: Overall Height: 1.040 INCHES NOMINAL IN; Width Across Flats: 1.630 INCHES NOMINAL IN; Style Designator: BULLS EYE; End Connection Type: UNABLE TO DECODE. 18 total characteristics are documented in the Federal Logistics Information System.

Is NSN 6680-00-905-2664 still in active supply?

NSN 6680-00-905-2664 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.
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