PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

P644UGage,compound Pressure-Vacuum,di

Ametek, Inc. Div Aerospace & Defense · NSN 6685-00-526-6931 · FSC 6685 · No Item Name Available
Verified by PartsTable
NSN 6685-00-526-6931 — this item is cataloged by the U.S. Government under National Stock Number 6685-00-526-6931. Primary manufacturer part number: P644U.
Features
  • Gage,compound Pressure-Vacuum,di — FSC 6685
  • Material: GLASS PROTECTIVE CRYSTAL
  • Surface Treatment: ENAMEL CASE
  • Material: STEEL CASE
  • Connection Type: EXTERNAL
  • Actuation Type: SINGLE BOURDON TUBE
  • Stud Quantity: 2
  • Unable to Decode: UNABLE TO DECODE
Applications
  • Applications requiring Glass Protective Crystal construction
General Description

The Gage,compound Pressure-Vacuum,di, cataloged under National Stock Number 6685-00-526-6931, is classified within Federal Supply Class 6685 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Ametek, Inc. Div Aerospace & Defense. Government technical data includes 28 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. 5 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN6685-00-526-6931
Primary Part NumberP644U
Item NameGage,compound Pressure-Vacuum,di
FSC / FSG6685 / 66 — No Item Name Available
ManufacturerAmetek, Inc. Div Aerospace & Defense
StatusACTIVE
MaterialGLASS PROTECTIVE CRYSTAL
Surface TreatmentENAMEL CASE
MaterialSTEEL CASE
Connection TypeEXTERNAL
Actuation TypeSINGLE BOURDON TUBE
Stud Quantity2
Unable to DecodeUNABLE TO DECODE
Connection Quantity1
Pointer TypeINDICATING
Pointer ColorWHITE
Scale Name for Which Pointer Is DesignedPRESSURE-VACUUM
Scale NamePRESSURE AND VACUUM
Scale Accuracy2 PERCENT RATING MIDDLE HALF OF RANGE,3 PERCENT REMAINDER; 3 PERCENT RATING ENTIRE RANGE
Scale Smallest Increment5.0 INCHES AND 5.0 POUNDS PER SQUARE INCH (PSI) LBS
Scale Inscription/background ColorWHITE FIGURES ON BLACK BACKGROUND
Connector Type VentNOT PROVIDED
Connection Size0.125 IN. NPT DIA IN
Bezel TypePRESSED ON W/ RETAINING BEZEL RING
Stud LocationBACK
Graduation Unit30.0 DEG FAHRENHEIT AND 25.0 POUNDS PER SQUARE INCH LBS
MaterialCOPPER ALLOY 511 ACTUATING ELEMENT
Scale TypeMULTIPLE
Dial Size2-1/2 IN. DIA IN
AdjustabilityNONADJUSTABLE
Connection LocationBACK, CENTER
Mounting MethodFLUSH PANEL
Scale Range+0.0 TO 30.0 INCHES OF MERCURY AND +25.0 TO 150.0 POUNDS PRESSURE PER SQUARE INCH LBS
Overall Diameter2.813 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 5
6685-00-515-5385101003 INTERCHANGEABLE
Gage,pressure,dial Indicating
Ametek, Inc. Div Aerospace & Defense
6685-00-531-201982-4084 INTERCHANGEABLE
Gage,pressure,dial Indicating
Marshall Excelsior Co
6685-00-581-2688164432 INTERCHANGEABLE
Gage,pressure,dial Indicating
Ametek, Inc. Div Aerospace & Defense
6685-00-684-1664101979 INTERCHANGEABLE
Gage,pressure,dial Indicating
Ametek, Inc. Div Aerospace & Defense
6685-00-727-8736 INTERCHANGEABLE
Gage,pressure,dial Indicating
Cross-Reference Index
Part NumberManufacturer
P644U Ametek, Inc. Div Aerospace & Defense (USA)
AD93 Rivers Bill Corp Coldmobile Div (USA)
Related Parts
6685-00-515-5385INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING
101003
6685-00-531-2019INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING
82-4084
6685-00-581-2688INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING
164432
6685-00-684-1664INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING
101979
6685-00-727-8736INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING

Frequently Asked Questions

What is NSN 6685-00-526-6931?

NSN 6685-00-526-6931 is a Gage,compound Pressure-Vacuum,di, manufactured by Ametek, Inc. Div Aerospace & Defense, classified under FSC 6685 (No Item Name Available). Status: active.

What are the part numbers for NSN 6685-00-526-6931?

NSN 6685-00-526-6931 has 2 cross-referenced part numbers: P644U (Ametek, Inc. Div Aerospace & Defense), AD93 (Rivers Bill Corp Coldmobile Div).

What NSN replaces 6685-00-526-6931?

There are 5 known substitutes for 6685-00-526-6931: 6685-00-515-5385, 6685-00-531-2019, 6685-00-581-2688 and 2 more. Verify interchangeability with system specifications before substitution.

What are the specifications of P644U?

Key specifications for P644U: Overall Depth: 1.078 INCHES NOMINAL IN; Material: GLASS PROTECTIVE CRYSTAL; Surface Treatment: ENAMEL CASE; Material: STEEL CASE. 29 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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