Seth Thomas Clock Movements

Ordering a Seth Thomas clock movement

The first step in replacing a Seth Thomas clock movement is to get the numbers off of the back plate of the movement. After getting the Seth Thomas clock movement numbers off of the brass back plate, it's time to convert these numbers to the real numbers of the actual manufacturer of the movement. Remember this only is good for the Seth Thomas movement numbers that start with an A like this A-401-001 . With the real movement numbers from the real manufacturer, we can then match the numbers up to the units in stock and you will have a brand new clock movement. The new movement will ship fast, be easy to install, less money than an overhaul, and be ticking in the fastest method.

Identifying the Seth Thomas clock movement

Seth Thomas Logo The numbers on the back of the mechanical German units start with the letter A. So if the movements number starts with the letter A and is of German origin, then it is most likely a Hermle made movement for the Seth Thomas company. This movement with the A on the back would have been made after around 1960.

Why order a new clock movement?

A new Seth Thomas clock movement's equivalent replacement can ship the same day you order it, usually from Huntington, MA via UPS. The new movement (if available) will cost less than a cleaning and overhaul of the old unit, will last much longer before having to worry about it again and will be up and running in your clock in a week or two rather than months down the road as in a repair. What is being offered is the same movement you have now but new, it is not some knock off replacement, it is the same movement. The modern Seth Thomas clocks were produced by manufacturers other than Seth Thomas. It will have their name on the movement to say that they designed the clock and its case, but they did not make the movement if the clock was produced in modern times (post 1960 or so).

What happened to the old one?

The clock oil that is put on the movement back when it was new has most likely solidified over a long period of time (20-30 years). What was once a lubrication to the clock movement has now turned to a sticky black abrasive substance and creates both resistance and wear on the movement. This wear and resistance will ultimately stop the clock from functioning properly because the pivots that ride in the holes of the movement's brass plates will not be able to spin as freely as they did in the past. The holes have become oblong instead of round so the pivot is pinched inside of the hole that it's supposed to spin inside of, and the oil is an abrasive rather than a lubricant.
Seth Thomas Number / New Movement Number Needed Please note, this list is often WRONG and is only a basic guide.
  • * Rear Pendulum Seth Thomas clock
  • ** Front or Rear Pendulum Seth Thomas clock
  • *** Needs new pendulum with it. Need to reverse direction of chimeblock.

Seth Thomas Historical Timeline

1785Birth of Seth Thomas in Wolcott, CT to James and Martha Thomas. Biographers state that he had limited education and was an apprentice to a carpenter and joiner with the creation of Long Wharf in New Haven, CT being one of his projects.
1799Daniel Tuttle takes in Thomas as an apprentice at 14 years old. His skills as a joiner and carpenter will prove useful in his later tasks of manufacturing clock movements and cases.
1807Thomas begins working with Eli Terry as a clockmaker apprentice near Waterbury, CT. Terry received an order to make 4,000 clocks which brought about methods of mass producing movements by using interchangeable clock parts. Many of these methods were inspired by Eli Whitney. Silas Hoadley joins the team and they create the famous wooden tall case clock. The name of their business is Terry, Thomas and Hoadley.
1810Hoadley is bought out by Thomas and Terry and the two gentlemen continue to produce the wooden tall case clocks.
1813Thomas sells his interest in the business back to Hoadley and sets up his own shop in Plymouth Hollow, CT. Thomas buys out Herman Clark’s clockmaking business which was producing wooden tall cases with wooden clock movements.
1816Seth Thomas licenses the right to use Eli terry’s wooden 30 hour shelf clock movement and labels it as E. Terry’s Patent Clock Made and Sold by Seth Thomas, Plymouth, Conn. These movements were used in Pillar and Scroll cases until 1830.
1842Beginning of brass clock movements which Thomas used in Ogee cases.
1845Brass, spring driven movements are now being used by 19th Century American Clockmakers. Thomas now abandons his wooden clock movements completely for the modern brass movements.
1853Seth Thomas Clock Company is incorporated.
1859Death of Seth Thomas. The business is now run by his three sons, Seth Thomas, Jr., Aaron, and Edward.
1866Plymouth Hollow changes its name to Thomaston in honor of Seth Thomas, Sr. All clock labels now denote this change. Another company was formed, Seth Thomas Sons and Company, which specialized in marine clocks and high end 15 day movements that were spring driven for mantel clocks.
1872Street clocks and tower clocks now being produced by Seth Thomas Sons and Company.
1879Seth Thomas Sons and Company merges with Seth Thomas Clock Company. The original company title of Seth Thomas Clock Company is used.
1884Seth Thomas Watch Company is established to make jeweled pocket watches. The first production of watches had 11 jewels in it and by 1886 the line had expanded to include 7, 11, 15, and 17 jewel movements.
1915Pocket watches are no longer produced.
1931Seth Thomas Clock Company becomes part of The General Time Instrument Company. The great grandson of Seth Thomas (Seth E. Thomas, Jr) is chairman of the board.
1932The Thomas family no longer controls The General Time Instrument Company due to the death of Seth E. Thomas, Jr.
1949Seth Thomas Clock Company becomes part of General Time Corporation.
1968General Time Corporation becomes part of Talley Industries.
1979The location of its headquarters moves from Thomaston, CT to Norcross, GA.
2001General Time Corporation ends. The Colibri Group buys out all of the assets of Seth Thomas.
2009Colibri Group discontinues all business with clocks and becomes a retailer of lighters and accessories bringing the Seth Thomas name into extinction.