Seth Thomas Mantel Clock Identification and Value

Has Seth Thomas ever caught your attention? Grand Central Terminal’s clock might be familiar to you if you haven’t seen it yet. A twenty-million-dollar price tag has been assigned to this exquisite four-sided clock. Seth Thomas manufactured this himself.

This clock company makes clocks that are so valuable that you might wonder if these clocks are of the same quality as those made by Seth Thomas. There may still be an antique clock in your family that dates to the 1800s.

You could still sell one of your clocks and turn a decent amount of money if you so desired. Although you shouldn’t anticipate any clocks to be valued at $20 million, doing so could still result in a sizable profit.

So, if you’re interested in learning more about Antique Seth Thomas clocks, their identification, and value, we’ve gathered all that information in this article!

The Seth Thomas Company’s History

Thomas’ history is evidently the beginning of the Seth Thomas Clock Company. As a young man, Seth Thomas worked in something completely unrelated to clockmaking, which he would go on to pioneer as a large-scale clock manufacturer.

Building homes and barns was the majority of Thomas’ early employment as an apprentice woodworker. However, Eli Terry, a clockmaker, hired him to work for him after noticing his woodworking abilities (in 1807).

After a few years and the production of hundreds of clocks, Thomas’ business partner decided to buy the company. He established his own clock business and constructed a mill as soon as he obtained the rights to Terry’s shelf clock.

The Seth Thomas Clock Company was founded at that period, and it is a significant US clock manufacturer. In 1853, it became a legal entity.

Mantel clock from 1880, manufactured by the Seth Thomas Clock Company
Mantel clock from 1880, manufactured by the Seth Thomas Clock Company (Image Source:Wikipedia)

In fact, Seth Thomas’ name was so important that it was used to create Thomaston, Connecticut, a new settlement that now bears his name. Plymouth Hollow, Connecticut was divided into this new hamlet.

Seth Thomas clocks are no longer produced after a turbulent history that saw them merge with, and then be acquired by, various businesses (General Time, Colibri Group, etc.). So, if you still possess one, you may anticipate that it will be rather valuable.

Identification of Seth Thomas Antique Mantel Clock

One of the most well-liked designs of clocks produced by the company were mantel clocks, so named because they often hang over fireplace mantels. As a result, it’s the type you have the greatest chance of having.

The next step is to identify whether your clock is an antique or a new piece and find out how old it is. In order to do so, the following factors must be considered:


Look for a label as the first step in figuring out whether you have a genuine Seth Thomas clock or not. You will need to search several areas for various components because Thomas used a variety of inventive branding techniques for his clocks.

A full paper label will almost probably be present or remains of a label. On the inside, the rear, or the bottom of the clock’s case, this may be found.

Antique Seth Thomas Adamantine Mantle Mantel Clock Labels
Antique Seth Thomas Adamantine Mantle Mantel Clock Labels
Seth Thomas Antique Mantel Clock Labels
Seth Thomas Antique Mantel Clock Labels

If a paper label has not been found, another option is to carefully inspect the pendulum inside the clock. The pendulum occasionally has Thomas’s name engraved on it.

Alternately, examine the clock face more closely. Thomas’ name was engraved on a few of the timepieces he made, directly above the number 6. This can be found, specifically, in clocks made in the years 1881 to 1888 or after 1913.

Antique 1900's Seth Thomas 8 day mantle clock, as is, for parts or repair
Antique 1900’s Seth Thomas 8 day mantle clock, as is, for parts or repair (Image Source: Ebay

If the issue still exists, you might be able to find a metal plate to fix it. This is also located elsewhere, such as inside the clock, besides the bottom. A patent number and an engraving of the Seth Thomas label should be present on the plate.

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Look at your mantel clock to see what kind of wood was used to make it. Seth Thomas made his clocks with walnut veneer up until about 1888. His manufacture started using walnut, cherry, and oak in 1888; starting around 1913, his business started building clock cases out of both mahogany and oak.

Determine the clock’s movement types. Wooden movements were used in the early Seth Thomas clocks, but in 1842 brass mechanisms took their place.

Look closely at the hands on the dial face since they are a very recognizable, identifying feature. A decoration that looked like a little bird with wings and a tail sticking out of the clock hand was added to the hands up until 1875, about a third of the way down from the top. Later clock hands had an arrow with a slightly curved tip and a spherical bottom. On each of the other clock hands, a circle extended one-third of the way up.

Antique 19th Century Original Seth Thomas Mantel Clock
Antique 19th Century Original Seth Thomas Mantel Clock (Image Source: Worthingtongalleries)

Evaluate the Materials and Style

Throughout the history of the clock manufacturer, Seth Thomas used a variety of materials. The styles changed as time went on. Take a look at your clock and think about the components it is comprised of. The following alterations to the materials, according to Collectors Weekly, will help you date your clock:

  • Mahogany frames with intricate carvings– Around 1830, Seth Thomas started framing clocks in the company’s later history.
  • Wooden movements– Wooden movements are found in Seth Thomas mantel clocks that are hundreds of years old. They frequently come with decorated cases with a scroll pattern.
  • Brass movements– Instead of the original wood movements, the business converted to brass ones in 1842.
  • Adamantine veneer– Seth Thomas began using this early plastic veneer on the clock faces in 1882.

Date Stamps

Finally, you probably want to know how old your mantel clock is. In fact, most vintage Seth Thomas clocks have a date mark on the bottom, making this method extremely easy.

When you find your date stamp, you might be confused, but don’t worry, the code isn’t as strange as it may seem!

As you can see from the date stamp, these four numbers are the reverse date of the clock, i.e., the year it was made. Thus, a code beginning in 5481, for instance, shows that the clock was manufactured in 1845.

The letter that follows the numerals is the last component of the date. The clock was produced in the month indicated by this letter. Letters A and L connect the first letter in the alphabet (A represents January) with the 12th letter (L represents December).

What do a Clock with Three Holes by Seth Thomas mean?

You might be interested in learning more about the three holes that can be seen on your Seth Thomas clock. Three winding holes are present on chiming clocks, each of which is responsible for powering a separate feature.

Make sure each of these holes is wound with your winding key. By powering the time train through the center hole, the clock stays on time. Powered by the hole on the left, the striking takes place at the top of the hour.

In addition to the chime, which emits a melodic sound every fifteen minutes, the right-side hole is also used to power the chime.

Simply wind the holes until the key can no longer be spun to hear all these sounds. The wrong way to wind the key is if it doesn’t turn at all.

Seth Thomas Mantel Clock Value

Mantel clocks can range substantially in price. As you certainly well know, the Seth Thomas Clock Company manufactured clocks for almost two decades, in a range of sizes and forms. Of course, not all of them are equally valuable. These guidelines might be used to determine the vintage Seth Thomas mantel clock’s current market value.

Determine a Date

It should come as no surprise that the antique clocks, particularly ones that Seth Thomas himself constructed, are the most valuable. You have a key element in determining value if you can determine when the clock was produced, whether from the label, style, or date stamp.

Analyze the Condition

The value of a Seth Thomas clock is greatly influenced by its condition, just like with any other antique. Look at the following:

  • Function– The functionality of the clock is first and foremost. Does it still accurately keep the time? When you wind it, as we previously described, does it strike and chime as it should? Your clock’s value will probably increase if the answer is yes.

There really is something you can do about it, though, if it doesn’t quite work as well as it once did. You could bring it to a clock repair, who could fix it using components from an old clock. An accurate clock that can keep time is worth more. A clock restorer could repair it using pieces from a vintage clock.

  • Glass condition– There can issues with the glass. Maybe the constant use has caused it to crack or chip. The clock’s value would be diminished if this were the case. You should consider yourself fortunate if your glass is still in decent shape, though. Because Broken and chipped glass detracts from value whereas good-looking glass adds to it.
  • Wood condition – After the glass condition, you must consider the wood’s condition. Has it been crazed, cracked, or was the restoration just done improperly, causing damage? The value of your clock might, regrettably, be adversely affected by this. Even though a wood case with a lovely patina can be more expensive, flaws, cracks, and poor restoration work could make it less valuable.
  • Condition of the clock face– The clock face condition is the next thing. A readable, well-lit clock face is a positive sign that your clock will be more valuable. A sign that shows indications of wear and tear is not nearly as good, though. If the clock face is still discernible and functional, it is valued considerably. It will be distracting if it has visible traces of restoration or hard use.
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The average of the ratings the clock obtained in the four areas of  glass condition, function, wood condition, and clock face can be used to determine its overall condition. Your clock may be highly valuable if it’s in excellent nick!

Validate With Clocks That Have Recently Sold

To determine the worth of your collectable mantel clock, look at recently sold examples after knowing as much as you can about it. The important thing is to disregard clocks that are still on sale. There is no guarantee that anyone will pay the asking price a seller chooses for a clock. Instead, check eBay for products that have been sold or browse auction records. Here are a few examples of Seth Thomas mantel clocks, along with their respective prices:

Seth Thomas Clock
Sold Cost
Excellent condition
It was in best condition, had just undergone maintenance, and worked perfectly.
Clock made by Seth Thomas around 1905
It was in “as found” condition. It did not keep time and without a pendulum.

The Perfect Blend of Functionality and Charm

More than merely a costly item for collection, a vintage Seth Thomas mantel clock. It serves as a useful component of your house as well, telling the time and adding vintage appeal to your mantel piece or shelf.

Price Guide for the Most Valuable Seth Thomas Antique Clocks

Vintage Seth Thomas clocks can be sold after a comprehensive appraisal on several websites, including eBay and auction sites or even in physical auctions.

Office Calendar Clock

Office Calendar Clock
Source:Office Calendar No. 8 by Seth Thomas, a rare find

The most expensive Seth Thomas clock, per Cottone Auctions, fetched $20,160 when it was auctioned off in 2021. This calendar belonged to an office, and it was made “about 1900,” as it was recorded. Although it ran for later than conventional clocks, it had several advantages.

In particular, the features of this clock, which are evocative of the earlier clocks, include a burl walnut accents, walnut case, and a pagoda top. The original carved metal dials, labels, pendulum, and directions were all intact in place.

Tall Regulator Wall Clock

Tall Regulator Wall Clock
Source:Tall Regulator Wall Clock from Seth Thomas

The third-highest price, $17,110, was paid for a tall regulator clock from Seth Thomas from the clocks manufactured in 1900s. This clock’s casing was made of walnut wood, and it was offered for sale in excellent original condition.

Shelf Violin Clock

Shelf Violin Clock
Source:Seth Thomas Reissue Violin Shelf Clock

A shelf violin clock was the second most expensive Seth Thomas clock piece ($17,250). Its aesthetic value would undoubtedly be its biggest selling point. The violin form is a distinctive and striking design that is likely to catch the eye of any onlookers.

Additionally, it was developed around September 1885, which makes it an early design according to the date stamp. The signed dial, clean label, and original glass are just a few of the other components that still exist.

Some other Valuable Mental clocks

The last thing we want to do is call attention to some other valuable mantel clocks from Seth Thomas company. Scroll mahogany and Pillar case clocks were the most expensive, selling for $3,000 and $4,600 respectively. Both had outstanding throwback features and were mainly in perfect condition.

Point to consider

Ask for a formal appraisal of the clock’s value before purchasing an expensive antique or vintage clock. To negotiate a reasonable price, use the appraisal.

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After Seth Thomas’s death in 1859, his son managed the business under his name. Up to its closure in 1980, the business kept producing clocks.

Unless you are sure about the authenticity of antique Seth Thomas clock, then don’t purchase a historic clock from an online auction site.


To validate the clock’s antique worth, you might consider dating it. However, it necessitates an additional fee for carbon dating or accurate assessment. However, ordinary collectors may certainly make things simpler by remembering a few facts.

You can prevent making bad decisions by having a thorough understanding of the topic. That’s why, you shouldn’t ignore the points when determining the best collectibles.


How can a Seth Thomas clock be dated?

Many Seth Thomas clocks made between 1881 and 1918 contain a date code inked on the bottom or back of the case. The year is typically written backwards, followed by a letter denoting each month, from A to L. April 1897, for instance, would show up as 7981 D.

How much is a Seth Thomas clock from 1880 worth?

For $550, a superbly maintained Seth Thomas clock from the 1880s made of adamantine and mahogany was sold. It was well-maintained and functioning as it should. For about $150, a Seth Thomas clock from about 1905 that was sold “as found.”

Are vintage Seth Thomas clocks worth anything?

Clock collectors and antiques enthusiasts who value craftsmanship and sophistication prize vintage Seth Thomas clocks, particularly wall clocks and mantle clocks.

How can I determine the worth of my clock?

Examine the clock for the marker’s label or signature. Examine the face, mechanism, and case carefully. Clocks with the maker’s name or a trademark stamped or inscribed on them are more valuable than clocks without any markings. If you can’t discover a label or stamp, you’ll have to figure out what kind of clock it is on your own.

Are Seth Thomas clocks still manufactured?

Seth Thomas launched the Seth Thomas Clock Company in 1813, and it began creating clocks right once. It was established in 1853 under the name “Seth Thomas Clock Company.” Although no production is now taking place, a full line of clocks with the Seth Thomas name are presently sold by another clock manufacturer for CST.

How much is a clock by Seth Thomas worth?

An “as found” Seth Thomas clock from around 1905 went for roughly $150.

How can the production date of an Antique Seth Thomas clock be determined?

Between 1881 and 1918, the bottom or case rear of most Seth Thomas clocks were inked stamped with codes. The year and a letter designating the month of production were reverse date stamped on numerous Seth Thomas clocks. Be mindful that not all Seth Thomas clocks have markings.

How do I determine the age of my Seth Thomas mantle clock?

Brands and Labels

On the clock’s back, bottom, or interior, look for the remnants of a label or the whole paper label.

Check the pendulum of the clock to see if there is an etching on it.

A metal plaque identifying the clock as an antique Seth Thomas clock can be found by carefully turning it over.

What kind of wood is used to make Seth Thomas clocks?

Wooden movements are seen in the antique Seth Thomas mantel clocks. They frequently come with decorated cases with a scroll pattern. Mahogany frames with intricate carvings – Around 1830, Seth Thomas started framing clocks in the company’s later history.

Adamantine clock: what is it?

The “Adamantine” black mantel clocks produced by Seth Thomas beginning in 1882 are well recognized. Glued to the wood case is a celluloid veneer called adamantine. White and black, as well as colored patterns like wood grain, onyx, and marble were used to create adamantine veneer.

Our Takeaway!

Seth Thomas, an American clockmaker, left behind a legacy that is unquestionable in its excellence and a legacy of excellence. A clock from his collection is a rare piece of history, so if you own one, then your clock is a piece of history.

We trust that this article Seth Thomas Mantel Clock Identification and Value has improved your knowledge of the background, significance, and process involved in identifying and dating your clock. Feel free to leave a comment below if you have any more queries or observations.

Thank You!

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