PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

20530Clock,marine,mechanical

The Chelsea Clock Llc · NSN 6645-00-936-8120 · FSC 6645 · No Item Name Available
Verified by PartsTable
NSN 6645-00-936-8120 — this item is cataloged by the U.S. Government under National Stock Number 6645-00-936-8120. Primary manufacturer part number: 20530.
Features
  • Clock,marine,mechanical — FSC 6645
  • Jewel Quantity: 11
  • Nonmagnetic Characteristic: NOT INCLUDED
  • Civil Date Indicator: NOT INCLUDED
  • Second Hand Type: SWEEP
  • Luminous Dial: INCLUDED
  • Plastic Case Color: BLACK
  • Material: PLASTIC CASE
Applications
  • Applications requiring Plastic Case construction
General Description

The Clock,marine,mechanical, cataloged under National Stock Number 6645-00-936-8120, is classified within Federal Supply Class 6645 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is The Chelsea Clock Llc. Government technical data includes 16 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 10 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN6645-00-936-8120
Primary Part Number20530
Item NameClock,marine,mechanical
FSC / FSG6645 / 66 — No Item Name Available
ManufacturerThe Chelsea Clock Llc
StatusCANCELLED
Jewel Quantity11
Nonmagnetic CharacteristicNOT INCLUDED
Civil Date IndicatorNOT INCLUDED
Second Hand TypeSWEEP
Luminous DialINCLUDED
Plastic Case ColorBLACK
MaterialPLASTIC CASE
Special MarkingsU. S. ARMY CLOCK,MESSAGE CENTER,M2
Winding Device LocationFACE
Maximum Running Time8.0 DAYS
Bezel TypeHINGED
ColorBLACK BACKGROUND
Dial Outside Diameter6.000 INCHES IN
Scale Range+0.0 TO 12.0 HOUR
Second Hand ColorSILVER
Striking MechanismNOT INCLUDED
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 10
3040-00-089-9851 INTERCHANGEABLE
Shaft,shouldered
4720-00-239-504120530 INTERCHANGEABLE
Hose,preformed
Gates Corporation
5930-00-296-726920530 INTERCHANGEABLE
Switch Subassembly
Roanwell, Llc
2530-00-836-782839114 INTERCHANGEABLE
Parts Kit,kingpin
Tld Wollard Llc
5330-00-889-5930 INTERCHANGEABLE
Seal,compressor
7510-01-174-4892197 INTERCHANGEABLE
Ribbon,inking
Frankel Mfg Co
2910-01-189-089520530 INTERCHANGEABLE
Retainer,rotor,transfer Pump
Stanadyne Corporation Dba Stanadyne Diesel Systems Div Diesel Systems
5120-01-349-1459 INTERCHANGEABLE
Wrench,box and Open End,combinat
5340-01-437-678620530 INTERCHANGEABLE
Plate,mounting
Grimes Aerospace Company
6530-01-623-698220530 INTERCHANGEABLE
Band,exercise,physical Therapy
Hygenic Corp the
Cross-Reference Index
Part NumberManufacturer
20530 PRIMARY The Chelsea Clock Llc (USA)
MILC3956 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
M2 The Chelsea Clock Llc (USA)
Related Parts
3040-00-089-9851INTERCHANGEABLE
SHAFT,SHOULDERED
4720-00-239-5041INTERCHANGEABLE
HOSE,PREFORMED
20530
5930-00-296-7269INTERCHANGEABLE
SWITCH SUBASSEMBLY
20530
2530-00-836-7828INTERCHANGEABLE
PARTS KIT,KINGPIN
39114
5330-00-889-5930INTERCHANGEABLE
SEAL,COMPRESSOR
7510-01-174-4892INTERCHANGEABLE
RIBBON,INKING
197
2910-01-189-0895INTERCHANGEABLE
RETAINER,ROTOR,TRANSFER PUMP
20530
5120-01-349-1459INTERCHANGEABLE
WRENCH,BOX AND OPEN END,COMBINAT
5340-01-437-6786INTERCHANGEABLE
PLATE,MOUNTING
20530
6530-01-623-6982INTERCHANGEABLE
BAND,EXERCISE,PHYSICAL THERAPY
20530

Frequently Asked Questions

What is NSN 6645-00-936-8120?

NSN 6645-00-936-8120 is a Clock,marine,mechanical, manufactured by The Chelsea Clock Llc, classified under FSC 6645 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 6645-00-936-8120?

NSN 6645-00-936-8120 has 3 cross-referenced part numbers: 20530 (The Chelsea Clock Llc), MILC3956 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), M2 (The Chelsea Clock Llc).

What NSN replaces 6645-00-936-8120?

There are 10 known substitutes for 6645-00-936-8120: 3040-00-089-9851, 4720-00-239-5041, 5930-00-296-7269 and 7 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 20530?

Key specifications for 20530: Jewel Quantity: 11; Nonmagnetic Characteristic: NOT INCLUDED; Civil Date Indicator: NOT INCLUDED; Second Hand Type: SWEEP. 17 total characteristics are documented in the Federal Logistics Information System.

Is NSN 6645-00-936-8120 still in active supply?

NSN 6645-00-936-8120 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.
PartsTable Design LLC · partstable.com