PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

M3971/1-5-SMeter,time Totalizing

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 6645-00-089-8842 · FSC 6645 · No Item Name Available
Verified by PartsTable
NSN 6645-00-089-8842 — this item is cataloged by the U.S. Government under National Stock Number 6645-00-089-8842. Primary manufacturer part number: M3971/1-5-S.
Features
  • Meter,time Totalizing — FSC 6645
  • Indicator Type: DRUM REGISTER
  • Maximum Measurement: 9999.90
  • Background Color: BLACK BACKGROUND ON HR WHEELS,WHITE BACKGROUND ON TENTHS WHEEL
  • Smallest Increment Indicated: 0.10
  • Body Depth: 3.000 INCHES MAXIMUM IN
  • Body Diameter: 2.210 INCHES MAXIMUM IN
  • Hermetic Protection: NOT PROVIDED
Applications
  • Applications requiring Aluminum or Steel or Plastic Case construction
General Description

The Meter,time Totalizing, cataloged under National Stock Number 6645-00-089-8842, is classified within Federal Supply Class 6645 (No Item Name Available) of the Instruments and Laboratory Equipment 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 21 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 11 commercial cross-references from 8 manufacturers, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN6645-00-089-8842
Primary Part NumberM3971/1-5-S
Item NameMeter,time Totalizing
FSC / FSG6645 / 66 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Indicator TypeDRUM REGISTER
Maximum Measurement9999.90
Background ColorBLACK BACKGROUND ON HR WHEELS,WHITE BACKGROUND ON TENTHS WHEEL
Smallest Increment Indicated0.10
Body Depth3.000 INCHES MAXIMUM IN
Body Diameter2.210 INCHES MAXIMUM IN
Hermetic ProtectionNOT PROVIDED
MaterialALUMINUM OR STEEL OR PLASTIC CASE
Reset FeatureNOT PROVIDED
Mounting ConfigurationTHREE 0.150 IN. DIA MTG HOLES ON 1.265 IN. RADIUS SPACED 120 DEG APART IN
Nondefinitive Spec/std DataB GRADE AND I TYPE
Marking ColorWHITE NUMERALS FOR HOURS,BLACK NUMERALS FOR TENTHS
Measurement UnitHOURS
Terminal Quantity2
Terminal TypeSOLDER LUG OR STUD
Mounting Flange Diameter2.875 INCHES MAXIMUM IN
Mounting MethodFLUSH
Movement TypeELECTRICAL
Voltage Rating4.0 VOLTS MINIMUM AND 40.0 VOLTS MAXIMUM
Unit TypeMOUNTED
Current TypeDC
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
5910-00-686-9136929-0016-000 INTERCHANGEABLE
Capacitor,fixed,ceramic Dielectr
Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems
3040-00-719-5344119379 INTERCHANGEABLE
Gearshaft,spur
Meggitt North Hollywood Inc
6645-00-864-6794M3971/1-6-S INTERCHANGEABLE
Meter,time Totalizing
Maxima Technologies & Systems Llc
6645-00-880-4893 INTERCHANGEABLE
Meter,time Totalizing
6645-01-057-7987 INTERCHANGEABLE
Meter,time Totalizing
6645-01-378-1175 INTERCHANGEABLE
Meter,time Totalizing
6645-01-442-0899 INTERCHANGEABLE
Meter,time Totalizing
Cross-Reference Index
Part NumberManufacturer
M3971/1-5-S Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
M3971/1-5 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-DTL-3971E Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-DTL-3971 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
73-0507 Department of Defense Project Manager-Mobile Electric Power (USA)
0109-0250 Drs Naval Power Systems Inc Dba Drs Power & Control Technologies Inc (USA)
119379 Hyster-Yale Group, Inc. (USA)
C1JZ10951A Ford Motor Company (USA)
119379 Hyster (europe) Ltd (GBR)
PC5120376 Power Components (deutschland) Gmbh (DEU)
771 Maxima Technologies & Systems Llc (USA)
Related Parts
5910-00-686-9136INTERCHANGEABLE
CAPACITOR,FIXED,CERAMIC DIELECTR
929-0016-000
3040-00-719-5344INTERCHANGEABLE
GEARSHAFT,SPUR
119379
6645-00-864-6794INTERCHANGEABLE
METER,TIME TOTALIZING
M3971/1-6-S
6645-00-880-4893INTERCHANGEABLE
METER,TIME TOTALIZING
6645-01-057-7987INTERCHANGEABLE
METER,TIME TOTALIZING
6645-01-378-1175INTERCHANGEABLE
METER,TIME TOTALIZING
6645-01-442-0899INTERCHANGEABLE
METER,TIME TOTALIZING

Frequently Asked Questions

What is NSN 6645-00-089-8842?

NSN 6645-00-089-8842 is a Meter,time Totalizing, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 6645 (No Item Name Available). Status: active.

What are the part numbers for NSN 6645-00-089-8842?

NSN 6645-00-089-8842 has 11 cross-referenced part numbers: M3971/1-5-S (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), M3971/1-5 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-DTL-3971E (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-DTL-3971 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 73-0507 (Department of Defense Project Manager-Mobile Electric Power) and 6 more.

What NSN replaces 6645-00-089-8842?

There are 7 known substitutes for 6645-00-089-8842: 5910-00-686-9136, 3040-00-719-5344, 6645-00-864-6794 and 4 more. Verify interchangeability with system specifications before substitution.

What are the specifications of M3971/1-5-S?

Key specifications for M3971/1-5-S: Indicator Type: DRUM REGISTER; Maximum Measurement: 9999.90; Background Color: BLACK BACKGROUND ON HR WHEELS,WHITE BACKGROUND ON TENTHS WHEEL; Smallest Increment Indicated: 0.10. 21 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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