PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

531Ammeter

Hoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc · NSN 6625-00-649-3881 · FSC 6625 · No Item Name Available
Verified by PartsTable
NSN 6625-00-649-3881 — this item is cataloged by the U.S. Government under National Stock Number 6625-00-649-3881. Primary manufacturer part number: 531.
Features
  • Ammeter — FSC 6625
  • Meter Body Diameter Behind Mounting Flange: 2.093 INCHES NOMINAL IN
  • Circuit Attachment Method and Quantity: 2 THREADED STUD
  • Meter Depth Behind Mounting Flange: 1.046 INCHES NOMINAL IN
  • Mounting Arrangement Style: THREE HOLE/STUD BOLT CIRCLE
  • Dial Scale Marking Color: BLACK SINGLE INDICATOR SINGLE RANGE
  • Circuit Current for Which Designed: DC
  • Sensitivity Rating: 50.0 MILLIVOLTS
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Ammeter, cataloged under National Stock Number 6625-00-649-3881, is classified within Federal Supply Class 6625 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Hoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc. Government technical data includes 30 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active. Unit of issue: EA.

Technical Specifications
ParameterValue
NSN6625-00-649-3881
Primary Part Number531
Item NameAmmeter
FSC / FSG6625 / 66 — No Item Name Available
ManufacturerHoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc
StatusACTIVE
Meter Body Diameter Behind Mounting Flange2.093 INCHES NOMINAL IN
Circuit Attachment Method and Quantity2 THREADED STUD
Meter Depth Behind Mounting Flange1.046 INCHES NOMINAL IN
Mounting Arrangement StyleTHREE HOLE/STUD BOLT CIRCLE
Dial Scale Marking ColorBLACK SINGLE INDICATOR SINGLE RANGE
Circuit Current for Which DesignedDC
Sensitivity Rating50.0 MILLIVOLTS
Scale Division Quantity20 SINGLE INDICATOR SINGLE RANGE
Movement TypeMOVING COIL, PERMANENT MAGNET
Style DesignatorROUND FLUSH MTG
ColorUNABLE TO DECODE
Overall Diameter2.687 INCHES NOMINAL IN
Mounting Bolt Circle Diameter2.390 INCHES NOMINAL IN
Movement Suspension MethodJEWEL PIVOT BASE
Mounting Facility Type and Quantity3 UNTHREADED HOLE(S)
Installation DesignPANEL
Accuracy in Percent-5.0 TO 5.0 AT FULL SCALE SINGLE INDICATOR SINGLE RANGE
Measurement Range-20.0 TO 20.0 AMPERES, DC SINGLE INDICATOR SINGLE RANGE
Mounting Hole Diameter0.128 INCHES NOMINAL IN
Meter Body Diameter Behind Mounting Flange2.093 INCHES NOMINAL IN
Circuit Attachment Method and Quantity2 THREADED STUD
Meter Depth Behind Mounting Flange1.046 INCHES NOMINAL IN
Mounting Arrangement StyleTHREE HOLE/STUD BOLT CIRCLE
Dial Scale Marking ColorBLACK SINGLE INDICATOR SINGLE RANGE
Circuit Current for Which DesignedDC
Sensitivity Rating50.0 MILLIVOLTS
Scale Division Quantity20 SINGLE INDICATOR SINGLE RANGE
Movement TypeMOVING COIL, PERMANENT MAGNET
Style DesignatorROUND FLUSH MTG
ColorUNABLE TO DECODE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Shelf Life Code0
Criticality CodeN
Unit of IssueEA
SMR CodeLN
Verified Substitutes 3
6625-00-188-3739327T0-50DCUA SUCCESSOR
Ammeter
Triplett (bluffton) Corporation Dba Lfe Instruments
6625-00-189-7026378-0470 SUCCESSOR
Ammeter
Continental Electronics Corp
6625-00-423-5345378-0471 INTERCHANGEABLE
Ammeter
Continental Electronics Corp
Cross-Reference Index
Part NumberManufacturer
531 PRIMARY Hoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc (USA)
Related Parts
6625-00-188-3739SUCCESSOR
AMMETER
327T0-50DCUA
6625-00-189-7026SUCCESSOR
AMMETER
378-0470
6625-00-423-5345INTERCHANGEABLE
AMMETER
378-0471

Frequently Asked Questions

What is NSN 6625-00-649-3881?

NSN 6625-00-649-3881 is a Ammeter, manufactured by Hoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc, classified under FSC 6625 (No Item Name Available). Status: active.

What are the part numbers for NSN 6625-00-649-3881?

NSN 6625-00-649-3881 has 1 cross-referenced part number: 531 (Hoyt Electrical Instrument Works, Inc. Dba Hoyt Electrical Instrument Works Inc).

What NSN replaces 6625-00-649-3881?

There are 3 known substitutes for 6625-00-649-3881: 6625-00-188-3739, 6625-00-189-7026, 6625-00-423-5345. Verify interchangeability with system specifications before substitution.

What are the specifications of 531?

Key specifications for 531: Meter Body Diameter Behind Mounting Flange: 2.093 INCHES NOMINAL IN; Circuit Attachment Method and Quantity: 2 THREADED STUD; Meter Depth Behind Mounting Flange: 1.046 INCHES NOMINAL IN; Mounting Arrangement Style: THREE HOLE/STUD BOLT CIRCLE. 30 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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