PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

644UGage,compound Pressure-Vacuum,di

Ametek, Inc. Div Aerospace & Defense · NSN 6685-00-228-3781 · FSC 6685 · No Item Name Available
Verified by PartsTable
NSN 6685-00-228-3781 — this item is cataloged by the U.S. Government under National Stock Number 6685-00-228-3781. Primary manufacturer part number: 644U.
Features
  • Gage,compound Pressure-Vacuum,di — FSC 6685
  • Scale Smallest Increment: 1.0 INCHES AND 1.0 POUNDS PER SQUARE INCH (PSI) LBS
  • Connection Location: BACK, CENTER
  • Scale Inscription/background Color: BLACK FIGURES ON WHITE BACKGROUND
  • Material: STEEL CASE
  • Scale Range: +0.0 TO 30.0 INCHES OF MERCURY AND +0.0 TO 15.0 POUNDS PRESSURE PER SQUARE INCH LBS
  • Material: GLASS PROTECTIVE CRYSTAL
  • Pointer Type: INDICATING
Applications
  • Applications requiring Steel Case construction
General Description

The Gage,compound Pressure-Vacuum,di, cataloged under National Stock Number 6685-00-228-3781, 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 4 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN6685-00-228-3781
Primary Part Number644U
Item NameGage,compound Pressure-Vacuum,di
FSC / FSG6685 / 66 — No Item Name Available
ManufacturerAmetek, Inc. Div Aerospace & Defense
StatusACTIVE
Scale Smallest Increment1.0 INCHES AND 1.0 POUNDS PER SQUARE INCH (PSI) LBS
Connection LocationBACK, CENTER
Scale Inscription/background ColorBLACK FIGURES ON WHITE BACKGROUND
MaterialSTEEL CASE
Scale Range+0.0 TO 30.0 INCHES OF MERCURY AND +0.0 TO 15.0 POUNDS PRESSURE PER SQUARE INCH LBS
MaterialGLASS PROTECTIVE CRYSTAL
Pointer TypeINDICATING
Stud LocationBACK
MaterialCOPPER ALLOY 511 ACTUATING ELEMENT
Connector Type VentNOT PROVIDED
Scale Name for Which Pointer Is DesignedPRESSURE-VACUUM
Connection Quantity1
Scale TypeMULTIPLE
Actuation TypeSINGLE BOURDON TUBE
Bezel TypeSNAP-ON
Mounting MethodFLUSH PANEL AND STUD(S) AND BRACKET(S)
Stud Quantity2
Pointer ColorBLACK
Connection Size0.156 IN. DIA HOSE IN
Connection TypeEXTERNAL
Scale Accuracy2 PCT MIDDLE HALF OF RANGE
Graduation Unit5.0 INCHES AND 3.0 POUNDS PER SQUARE INCH LBS
AdjustabilityNONADJUSTABLE
Dial Size2 IN. DIA IN
Scale NamePRESSURE-VACUUM
Reference Number Differentiating CharacteristicsAS DIFFERENTIATED IN ACTUATING ELEMENT DATA,MULTIPLE READING SCALE,DIAL DATA,CASE DATA,GLASS PROTECTIVE CRYSTAL,AND CONNECTION DATA
Surface TreatmentENAMEL CASE
Overall Diameter2.250 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
6685-00-618-3519087896 INTERCHANGEABLE
Gage,compound Pressure-Vacuum,di
Ametek, Inc. Div Aerospace & Defense
6685-01-096-17111001743 INTERCHANGEABLE
Gage,compound Pressure-Vacuum,di
Tld Ace Corp Div Tld Ace
6685-01-096-171210026REVA INTERCHANGEABLE
Gage,compound Pressure-Vacuum,di
Tld Ace Corp Div Tld Ace
6685-01-307-2114844U INTERCHANGEABLE
Gage,pressure,dial Indicating
Ametek, Inc. Div Aerospace & Defense
Cross-Reference Index
Part NumberManufacturer
644U Ametek, Inc. Div Aerospace & Defense (USA)
844U Ametek, Inc. Div Process & Analytical Instruments Division (USA)
1-119987 Simpson Electric Company, Inc. (USA)
C844U Ametek, Inc. Div Aerospace & Defense (USA)
Related Parts
6685-00-618-3519INTERCHANGEABLE
GAGE,COMPOUND PRESSURE-VACUUM,DI
087896
6685-01-096-1711INTERCHANGEABLE
GAGE,COMPOUND PRESSURE-VACUUM,DI
1001743
6685-01-096-1712INTERCHANGEABLE
GAGE,COMPOUND PRESSURE-VACUUM,DI
10026REVA
6685-01-307-2114INTERCHANGEABLE
GAGE,PRESSURE,DIAL INDICATING
844U

Frequently Asked Questions

What is NSN 6685-00-228-3781?

NSN 6685-00-228-3781 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 6685-00-228-3781?

NSN 6685-00-228-3781 has 4 cross-referenced part numbers: 644U (Ametek, Inc. Div Aerospace & Defense), 844U (Ametek, Inc. Div Process & Analytical Instruments Division), 1-119987 (Simpson Electric Company, Inc.), C844U (Ametek, Inc. Div Aerospace & Defense).

What NSN replaces 6685-00-228-3781?

There are 4 known substitutes for 6685-00-228-3781: 6685-00-618-3519, 6685-01-096-1711, 6685-01-096-1712 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 644U?

Key specifications for 644U: Scale Smallest Increment: 1.0 INCHES AND 1.0 POUNDS PER SQUARE INCH (PSI) LBS; Connection Location: BACK, CENTER; Scale Inscription/background Color: BLACK FIGURES ON WHITE BACKGROUND; 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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