Antique Seth Thomas Mantle Clock: Identification and Value Guide

Seth Thomas Mantle clock
(Source: Mearto)

Antique Seth Thomas clocks offer a quick glimpse into the world of skillful clock decoration and a clock-making culture that has survived for centuries while maintaining a significant position as one of the finest earliest clocks in the antique universe.

The average price of an Antique Seth Thomas Mantle clock is about $100. Still, depending on the current market situation, you can find a limited-edition mantle clock for $500 and above.

This article is compiled to inform you explicitly about the evolution of Seth Thomas Mantle Clocks to help you easily identify your clock and determine the ultimate value.

History of Antique Seth Thomas Mantle Clock

Renowned clockmaker Seth Thomas, a native of Wolcott, Connecticut 1785, worked for Eli Terry, another famous clockmaker, in 1807. In 1810, Seth purchased Eli’s factory in conjunction with Silas Hoadley and Heman Clark’s factory in Plymouth Hollow in 1813.

Thomas promoted Clark’s style of wooden movement and started producing this wooden style of clocks in 1817.

These clocks were housed in pillar and scroll cases, and a scene is drawn on the bottom third of the clock cases until 1830 when the bronze-inspired glass with other styles gained popularity.

The frame of the Thomas Mantle clocks in 1830 was usually made in a deep, detailed and strong mahogany wood.

Brass movements emerged on the scene in 1842 and were kept in the O.G. case produced from 1842 through 1913.

The era of wood movements maxed out in 1845, and Mr. Thomas made an important move to integrate Seth Thomas Clock Company to maintain the legacy of the business.

Thomas passed on in 1859, and Plymouth Hollow was christened Thomaston to honor his life and works in 1865. The company advanced further and deeper into the business and produced over 135,000 clocks a year by 1885.

Here’s a history of Seth Thomas himself.

How to Date Seth Thomas Mantle Clock

To properly determine the date of your antique Seth Thomas clock, check the clock’s body for inscriptions or years on the dial or movements. If the back of the clock can be removed, use a magnifying lens to check the inner movements.


An 1817 Antique Seth Thomas Mantle Clock
An 1817 Antique Seth Thomas Mantle Clock                         (Source: Pinterest)

You can also uncover the date by looking at the material the clock is made from; older Seth Thomas clocks are made from wood, dating between 1817 and 1830.

After 1830, the Thomas company adopted brass movements in its clock. Moving past 1845, wood movements eventually went out of circulation.

The spring-driven clocks debuted in 1855 and 1860 with the regulator clocks. From 1863 to 1970, perpetual clocks dominated the market.


A 1910 Antique Seth Thomas Mantle Clock
A 1910 Antique Seth Thomas Mantle Clock                                                       (Source: Etsy)

The Seth Thomas Mantle Clock is designed to sit on shelves and tables, and for his·· 1880s merchandise, he used more walnut, cherry and oak wood.

However, one feature of Seth Thomas Clocks made in 1880 through 1918 was ink stamps. These codes are on the base or behind the cases.


An 1881 Adamantine Mantle Clock
An 1881 Adamantine Mantle Clock                                                (Source: Liveauctioneers)

From 1881 to 1888, Seth Thomas’s name appeared on the clock dials. Seth Thomas started using plastic veneers on the clock faces.

They also have date codes embossed in deep ink on their cases and underneath them. These years are usually written backwards and spanned from the letter A-L representing the production month.

The Adamantine black Mantle clocks are made from Celluloid veneer attached to a wood case. They often come in black and white colors and patterns like onyx, wood grain and marble.

Below is a video analyzing Adamantine clocks.

Most Valuable Antique Seth Thomas Mantle Clocks

Here’s a list of five most valuable and rarest Seth Thomas Mantle Clocks ever sold. The prices and data in this table are compiled from verified sources and void of imitation. Any resemblance to an existing list is purely coincidental.

Release Date
Seth Thomas Sonora Chime Mantle Clock
Seth Thomas Pillar & Scroll Mantle Clock

1. Name: Seth Thomas Sonora Chime Mantle Clock

Release Date: 1900

Price: $2,726

1. Name Seth Thomas Sonora Chime Mantle Clock
(Source: Skinneric)

A rare Seth Thomas 1900 Sonora Chime Mantle Clock in a brass coated lancet-shaped case with a silver dial inscribed with Seth Thomas Sonora Chime and raised Arab numeric number indicators, 8-day time, strike and Sonora quarter-chime on alarm bells.

2. Name: Seth Thomas Pillar & Scroll Mantle Clock

Release Date: 1835

Price: $590

2. Name Seth Thomas Pillar & Scroll Mantle Clock
(Source: Caseantiques)

An 1835 Seth Thomas Pillar and Scroll mahogany mantel clock produced by the Seth Thomas company with a painted scene glass panel showing a white pillared building, closely resembling Mount Vernon. The clock has a 30-day movement, painted surface with tinseled and floral details, brass coated fittings, ornaments and pendulum, with iron mass.

How to Determine the Value of Seth Thomas Mantle Clock

These unique and functional clocks have survived for over two decades. It’s not unusual that there’s significant variation in the value of Seth Thomas Mantle Clocks. Here’s how to correctly determine these values.


Individual choice can affect the value of any antique item, including Seth Thomas Mantle Clocks; if people attach importance to something regardless of its perceived value (if it’s less in real-time), demand will increase and the value will follow the same pattern.


The more detailed and complex your Antique Seth Thomas clock design is, the more likely it is to be highly sought after and more valuable. An extra tip is if the design is themed or belongs to the rare category- these usually sell for about a thousand dollars or even more.

Market Factors

The forces of demand and supply play a huge role in determining the value of an item. An 1800 mantle clock may be highly sought after on the east coast and have little relevance on the west coast. Naturally, people will gravitate toward whatever is in vogue at that time.

Consult an Appraiser

Appraisers are widely recognized for helping collectors and buyers evaluate their antique items and come up at a select value. Quickly locate an appraiser to help you determine the value of your old Seth Thomas Mantle Clock.

How Old is Your Mantle Clock?

The first clocks made by the Seth Thomas company are the most valuable. Getting the actual date of your clock either from the style, the logo, company marks, or the label is very important for assigning a value to your item.

Check the Condition

Like any other antique, the condition of your clock significantly affects the perceived value. If your clock, no matter how aged, still functions properly and keeps to time, then the value is still intact.

The condition of the wood is also a factor. Chipped, Cracked, and worn-out wood affects the aesthetic value of your clock, and for buyers who are more focused on the appearance of their objects, this may have a large effect on the value.

If the face of your clock is luminous, readable and bright, it has a reasonable value. Be careful with your clock to not roughen the face. Cracked glass also reduces the value of your clock.

Ensure that your Mantle clock is well kept and away from human contact.

Compare Prices

You can also consult recently sold clocks to determine the current price of your antique clocks. Surveying the market will help you come to a definite sum and not sell yourself short.

Stay on course and search for sold items only. Items still currently on sale can fluctuate and sell for less than what you initially saw.

A 1920  Antique Seth Thomas Rosewood Mantle clock sold for $169 recently on Etsy while a 1940 Seth Thomas Mantle Clock sold on Chairish for an undisclosed price and a 1921 Seth Thomas Mantle clock on invaluable also for an undisclosed price.


The harder it is to find a particular model of a clock, the more valuable and highly sought after it gets. If you have a limited edition or a special run production in your care, you’re in for a big return on sales.

Is It a Restored Piece?

Suppose your Seth Thomas Mantle clock has lost a vital part that has been replaced or has been completely retouched until the Antique factor is no longer obvious. In that case, the value may likely be reduced by a great deal.

Study The Materials

From plain wood to mahogany with intricate details, these materials are not just there for fun, and no artisan used them with the intent to sell them at a normal price. In other words, the rarer the wood or, the more complex the clock material is, the more valuable the clock gets.

Is it Trademarked?

Examine the body of your Seth Thomas mantle clock closely to find company marks or any sign indicating ownership and originality. Although not all Seth Thomas are marked, collectors and buyers still have a flair for marked ones anyway.

You’ll need a magnifying lens and light bright enough to see the marks as they vary in size properly.

How to Identify Seth Thomas Mantle Clock

Many changes were made while designing these clocks, making them a bit difficult to identify. But not to worry, we’ll help you fix that challenge by providing a detailed guide.

Study the Movements

One of the easiest and most accurate ways to identify a Seth Thomas Mantle clock is to study the movements closely by opening the back. The earliest Seth Thomas clocks used wood movements until 1842 when the company adopted brass movement for the clocks.

The Hands

1875-1910 Seth Thomas Mantle Clock Face
1875-1910 Seth Thomas Mantle Clock Face (Source: Pinterest)
1820 Seth Thomas Antique Clock
1820 Seth Thomas Antique Clock (Source: Pinterest)

Study the hands on your clock dial. The hands are an essential tool for identifying your clock. Until 1875, Mantle clock hands had a coating that went all the way down from the top, which looked like a little bird with its wings and tail dangling from the clock hand.

Subsequently, the emerging clocks had hands with a gently formed arrow with a round bottom on their tips. In contrast, the other clock hands had a circle one-third extending up on the individual indicators.

Join a Forum

A forum is a union of people with a shared interest or passion for collecting an item or holding conversations about them.

Like every antique item, Seth Thomas clocks also have a group of admirers and loyal collectors with a shared interest in spotting limited edition pieces and rare models and organizing exhibitions. Find a forum near you and join to make identification easier and faster.

The National Association of Watch and Clock Collectors is an excellent start towards your collecting journey.

Find a Label

Find a Label
(Source: Cottageclockshop)
Find a Label 1
(Source: Cottageclockshop)

Examine the body of your clock and look for the Seth Thomas label. It’s usually inside, at the bottom or behind your clock case. There’re also metal labels on some clocks and stamped pendulums with the Seth Thomas name.

Thomas clocks usually used had paper labels throughout the years. His Mantle pendulum clocks dominated the market.


(Source: Ourpasttimes)
Trademarks 1
(Source: eBay)

To spot the trademark, turn your clock to the other side and find a metal plate indicating that your clock is from Seth Thomas’s factory; if you don’t see it here, open it and check inside.

If your clock has a patent, Seth Thomas added a patent number and his company trademark on the metal plate.

Look for the Date Stamps

Look for the Date Stamps
(Source: Ourpasttimes)

You’ll find date stamps beneath almost every Seth Thomas clock. They appear in letters and numbers and take special skills to interpret them. But there’s a trick; Every code begins with four digits and ends with a letter of the alphabet, with the numbers being the year written backwards.

For the letters, they mean the production month, like “A,” which means January and “L,” which means December. So, if you see a code 5981A, it simply means Seth Thomas company made the clock in January 1895.


(Source: Ourpasttimes)
Designs(Source Ourpasttimes)
(Source: eBay)

As the years passed, the Seth Thomas clock factory updated its styles to fit into the aesthetics of the day and modify designs. This is one of the ways you can identify and get other important information about your item. Seth also changed the hands of his clocks from time to time during production.

You should inspect the face of your clock, as Seth Thomas usually adds his name to the dial or at the center just above the number 6 on the dial.

Appraise Your Clock

One of the first things you must do to aid easy identification is a check in with an appraiser and get them to closely examine your antique Seth Thomas clock from top to bottom.

Appraisers are already used to the parts and how to maintain them properly. In the antique world, they’re our knights in shining armor.

You can visit for a quick appraisal.

Study the Materials

Seth Thomas’ company used various materials at different times for different clocks. Examining your clock material closely can help you rightly identify it.

The first generation and the oldest Mantle clocks movements were wooden. They had cases which were painted and bore scroll details.

Subsequently, in 1830, the company changed their designs by framing the clocks in carved mahogany wood tastefully sculpted. By 1842, brass movements replaced wooden ones.

Finally, in 1882, Seth Thomas began using Adamantine Veneer. This plastic veneer is a thin strip used on furniture, closely resembling laminate, and is made from a light layer of wood.

In 1888, he incorporated Walnut, Cherry and Oak trees into his production. In 1913, the company fully used mahogany and oak to construct the case.

Check the Pendulum

A real and true pendulum inside a clock must have some inscription or sign. Sometimes, Thomas often adds a photo of his clock factory on these pendulums with his name surrounding the outer lining at the edge.

Consult Online Guides and Books

So many publications are available with pictures and sections on properly identifying and spotting authentic Antique Seth Thomas Mantle Clock. Simply walk into a bookstore and get yourself a pair or consult the links below to access a book

Where to Sell Antique Seth Thomas Mantle Clock

You don’t have to throw away your antique Seth Thomas mantle clock; you can simply sell them at any of the platforms below and make a few bucks.


You can sell off your clock elegantly and make twice the profit by organizing an auction online or at a walk-in center. All you need to do is drop a price and wait for the highest bidder. Auctions have the widest reputation for being the best platform for selling Antique items.

Online Antique Stores

Surf the web for online antique stores and upload your item to get them sold off in no time. Always remember to add one or two extra details about your clock that’ll set it aside from the rest and bring buyers in numbers.

Art Centers

Art centers are scattered over America that specialize in selling antique art items, including Seth Thomas Mantle clocks. The advantage of shopping at the art center is that it gives you a first-hand look at your article of interest and no room for surprises.

Thrift Shop

Stuff sold in thrift shops is majorly pre-owned that was dropped off by its owners to clear off space or exchange for something newer. If your interest in these clocks is not necessarily a new one or one in near mint condition, then head on to a nearby thrift shop.

Where to Buy Antique Seth Thomas Mantle Clocks

We’ve arranged a list of places you can purchase one or more antique Seth Thomas Mantle clocks should in case your interest leans towards them.

Online Sources

Sites like eBay, Etsy and the likes have plenty of options and styles of antique Seth Thomas Mantle clocks for you to pick from at different prices tailored to fit your budget. You can even enjoy side attractions like discounts and bonuses on your purchases.


Due to its nature as a vital piece of art and human history, we can assure you that antique Seth Thomas Mantle clocks are hot cakes and highly sought after at auctions, so you’ll likely find an array of clocks to pick from.

Online Antique Stores

Rubylane, GoAntiques and a host of others have developed a large clientele over the years and are widely known for selling different styles of antique clocks. Numerous retailers engage interested customers on this platform.

Flea Markets

Flea markets might be small, but they have a lot of hidden treasures in them. Take a visit to one, and you might get lucky enough to find an old mantle clock lying in the rubble at a very discounted price.

Estate Sales

Estate sales are used for disposing of a large number of materials owned by someone who is dead or intends to sell off their properties to aid a move.

So, if your grandfather or uncle passes on and they have an attic full of Seth Thomas mantle clocks, you can clear it out by organizing a grand estate sale and sell for people at whatever price you wish.

Antique Clock Stores

Antique clock stores have a large inventory of old, large and rarest clocks that have existed for decades and survived centuries of human civilization. Take a trip to the nearest antique clock store to copy a piece for yourself.

Final Thoughts

Seth Thomas Mantle clocks are old but have remained in the hearts of avid collectors as a masterpiece and important historical figures.

You must pay enough attention to your antique clocks and the collecting process. The tips below will help you through that.

  • Seth Thomas Mantle clocks are high value, and purchasing has to be done carefully and monitored; always contact an appraiser to get an idea of the price.
  • Avoid auction sites if you’re unsure of your antique clock’s authenticity, it’s better to be safe than sorry.
  • Ensure your clock hands are in good condition by lubricating them and replacing old oil.

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