PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

400252Clock,panel

Waltham Aircraft Clock Corp · NSN 6645-00-880-5927 · FSC 6645 · No Item Name Available
Verified by PartsTable
NSN 6645-00-880-5927 — this item is cataloged by the U.S. Government under National Stock Number 6645-00-880-5927. Primary manufacturer part number: 400252.
Features
  • Clock,panel — FSC 6645
  • Dial Quantity: 1
  • Material: ALUMINUM CASE
  • Specification/standard Data: 81349-MIL-C-6499 GOVERNMENT SPECIFICATION
  • Escapement Type: LEVER
  • Chime Mechanism: NOT INCLUDED
  • Nonmagnetic Characteristic: INCLUDED
  • Second Hand Color: BLACK, LUSTERLESS
Applications
  • Applications requiring Aluminum Case construction
General Description

The Clock,panel, cataloged under National Stock Number 6645-00-880-5927, is classified within Federal Supply Class 6645 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Waltham Aircraft Clock Corp. 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. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN6645-00-880-5927
Primary Part Number400252
Item NameClock,panel
FSC / FSG6645 / 66 — No Item Name Available
ManufacturerWaltham Aircraft Clock Corp
StatusCANCELLED
Dial Quantity1
MaterialALUMINUM CASE
Specification/standard Data81349-MIL-C-6499 GOVERNMENT SPECIFICATION
Escapement TypeLEVER
Chime MechanismNOT INCLUDED
Nonmagnetic CharacteristicINCLUDED
Second Hand ColorBLACK, LUSTERLESS
Nondefinitive Spec/std DataA13A2 TYPE
Movement TypeMECHANICAL
Maximum Running Time8.0 DAYS
Surface TreatmentPAINT LUSTERLESS CASE
Surface Treatment Document and ClassificationFN-10, NORTH AMERICAN PHILIPS CONTROLS CORP MFR REF SINGLE TREATMENT RESPONSE CASE
Winding Device LocationFACE
Increment in Hours12.000
Second Hand TypeSWEEP
Mechanical Movement TypeSPRING WOUND
Outside Diameter1.875 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
5950-00-022-7474 INTERCHANGEABLE
Transformer Assembly
6645-00-084-1424 INTERCHANGEABLE
Clock,panel
6645-00-150-6526400202 INTERCHANGEABLE
Clock,panel
Waltham Aircraft Clock Corp
5998-00-491-3968400192 INTERCHANGEABLE
Circuit Card Assembly
Astronics Test Systems Inc
5950-00-523-927442961 INTERCHANGEABLE
Coil,electrical
L3harris Technologies, Inc Div Space & Airborne Systems
5950-00-899-5544 INTERCHANGEABLE
Coil,radio Frequency
5835-01-196-8418400192 INTERCHANGEABLE
Standby Power
Dictaphone Corporation
5315-01-207-1354400192 INTERCHANGEABLE
Pin
Esco Corporation
6645-01-235-9465 INTERCHANGEABLE
Clock,panel
5905-01-276-5509 INTERCHANGEABLE
Resistor,fixed,film
Cross-Reference Index
Part NumberManufacturer
A13A2 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
400252 PRIMARY Waltham Aircraft Clock Corp (USA)
MILC6499C Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
400252 Waltham Clock Co Inc (USA)
400192 Waltham Clock Co Inc (USA)
Related Parts
5950-00-022-7474INTERCHANGEABLE
TRANSFORMER ASSEMBLY
6645-00-084-1424INTERCHANGEABLE
CLOCK,PANEL
6645-00-150-6526INTERCHANGEABLE
CLOCK,PANEL
400202
5998-00-491-3968INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
400192
5950-00-523-9274INTERCHANGEABLE
COIL,ELECTRICAL
42961
5950-00-899-5544INTERCHANGEABLE
COIL,RADIO FREQUENCY
5835-01-196-8418INTERCHANGEABLE
STANDBY POWER
400192
5315-01-207-1354INTERCHANGEABLE
PIN
400192
6645-01-235-9465INTERCHANGEABLE
CLOCK,PANEL
5905-01-276-5509INTERCHANGEABLE
RESISTOR,FIXED,FILM
6645-01-383-7231INTERCHANGEABLE
CLOCK,PANEL
A13A2
1680-01-562-5017INTERCHANGEABLE
COVER,AIRCRAFT,MATE
40019-2

Frequently Asked Questions

What is NSN 6645-00-880-5927?

NSN 6645-00-880-5927 is a Clock,panel, manufactured by Waltham Aircraft Clock Corp, classified under FSC 6645 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 6645-00-880-5927?

NSN 6645-00-880-5927 has 5 cross-referenced part numbers: A13A2 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 400252 (Waltham Aircraft Clock Corp), MILC6499C (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 400252 (Waltham Clock Co Inc), 400192 (Waltham Clock Co Inc).

What NSN replaces 6645-00-880-5927?

There are 12 known substitutes for 6645-00-880-5927: 5950-00-022-7474, 6645-00-084-1424, 6645-00-150-6526 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 400252?

Key specifications for 400252: Dial Quantity: 1; Material: ALUMINUM CASE; Specification/standard Data: 81349-MIL-C-6499 GOVERNMENT SPECIFICATION; Escapement Type: LEVER. 19 total characteristics are documented in the Federal Logistics Information System.

Is NSN 6645-00-880-5927 still in active supply?

NSN 6645-00-880-5927 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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