Seth Thomas Small Mantel Clock with B-48-J Movement

This cute little Seth Thomas mantel clock is 9 13/16 inches tall and 7 3/8 inches wide. It has a white enamel dial, and the minute hand is 1 3/4  long. It strikes the hour and half-hour.

The model B-48-J movement in this clock looks like a forerunner of the No. 120 movement in my earlier post. Superficially they look similar, but the gearing and escapement are different. Both movements have stationary barrels to contain the mainsprings. This movement has the barrels mounted to the back plate, but the 120 has them mounted to a removable lower front plate. This means that one can replace the mainsprings on the No. 120 movement without separating the  plates. This movement (B-48-J), however, requires disassembly to replace a mainspring.

See more photos.

Repair job 5737. A previous repair shop had installed bushings that were way too tall (3 times the required height). I polished the pivots and installed proper bushings. I also straightened bent teeth on the canon pinion, reduced the hand-set tension (to make the minute hand easy enough to turn) and replaced one missing pinion wire (or trundle).

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  1. Hello,
    I have a 1909 Seth Thomas Turin with a 48J movement. This clock was my GG parents, a wedding gift to them in 1909. Do you know of any good clock repair shops in the St Louis area…..or is it possible for me to find information and parts to repair it on my own. I am pretty mechanically inclined but have never worked on a clock. The left side spring will not wind, it is fused……the right side will turn but seems loose. I would love to get this back in working order. Thanks in advance for any help or tips.
    Steve F

  2. Hello Bill,what beautiful work.a true horologist.I’m trying to restore a Seth Thomas. 4bevelled glass case mantel clock.Almost complete except,I’m looking for the correct hands to fit the,3 7/8ths inches dial.I think the hands may be similar dimensions to the ,ST 48j clock(completely different an younger model).I had bought some ST hands but,unfortunately,the pivot holes are too big. I’ve measured exactly,and the measurements I have(approx), second hand pivot (round) hole is 2 mm. The small hand(square) is 1.5mm. Having difficulty finding these correct hands.I would so much appreciate any advice,help,you may offer,in order I can finish this,my 1st project(just started my love of clocks interest,since my retirement).I would happily buy any of the items(if available),Most grateful if you could find the time to respond,nevertheless,I shall continue to follow your excellent site,with great inspiring interest. Sincere thanks. George.

  3. i have a simular model called an ‘Eton’. it has an inlaid design on front but otherwise the same. it has a 48j movement. any idea when this clock was made?

  4. I have a Seth Thomas with a 48 Q which looks the same as your 48 J. The rack tail has been repaired and I need to fix it.The chime doesnt work correctly.Thanks for the photo of yours as I can see what it should look like.I have been working on clocks about 15 years and i Love it.I have the same mantle clock case as yours

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