Seth Thomas Antique Mantel Clocks Features and Values

Updated February 18, 2020
Seth Thomas Antique Mantel Clock

Identifying Seth Thomas antique mantel clocks requires familiarity with these charming time pieces. Learn about the materials used, the styles, and how to assign a value to these beautiful clocks.

How to Identify a Seth Thomas Clock

Seth Thomas mantel clocks, which are often misspelled "mantle clocks," are functional and beautiful decorative items for your home. Designed to sit on a shelf or mantel, they not only tell the time but also offer a glimpse at the art of clock-making and the work of a master. According to Collectors Weekly, Thomas began making these clocks in 1817. Over the years, the designs changed, giving collectors some clues when it comes to identifying and dating the clocks. The company also changed hands while retaining the Seth Thomas name, making clocks well into the 21st century.

Look for Labels

The first step in identifying your clock is to look for the Seth Thomas label. You can find the label on the inside, back, or bottom of the clock case. You'll also see stamped metal labels on some clocks, as well as engraved pendulums featuring the Seth Thomas name. The Antique Clocks Identification and Price Guide offers photos of many of the labels you may see, as well as dating information based on the style and text of the label.

Check for Date Stamps

Many antique Seth Thomas clocks also feature date stamps on the bottom of the clock. These stamps are a series of numbers and letters, and they can be difficult to decode. Fortunately, once you know the trick, you'll find it's quite simple. Each code starts with a four numbers and ends with a letter. The numbers are the year backwards. The letter represents the month with "A" standing for January and "L" standing for December. For instance, a code of 2981D would indicate a clock that was made in April of 1892.

Seth Thomas clock label

Examine the Style and Materials

Seth Thomas used different materials at different times in the clock maker's history. The styles also changed over the years. Take a look at your clock and think about what it is made from. Collectors Weekly reports that the following changes in materials can help you date your clock:

  • Wood movements - The very oldest Seth Thomas mantel clocks feature movements made of wood. They often have painted cases with a scroll design.
  • Carved mahogany frames - Later in the company's history, around 1830, Seth Thomas began framing clocks in beautifully carved mahogany wood.
  • Brass movements - In 1842, the company switched to brass movements instead of the original wood.
  • Adamantine veneer - Starting in 1882, Seth Thomas used this early plastic veneer on the faces of its clocks.
Seth Thomas Clock

Value of Seth Thomas Mantel Clocks

Because the Seth Thomas company made mantel clocks for almost 200 years, there is a lot of variation in the value of the clocks. Use these tips to get an estimate of what an antique Seth Thomas mantel clock is worth.

Assign a Date

Not surprisingly, the earliest clocks, especially those actually made by Seth Thomas, are worth the most money. If you can get a sense of the date your clock was made, either from the label, style, or date stamp, you have an important factor in assigning value.

Seth Thomas Clock

Assess Condition

As with any antique, the condition of a Seth Thomas clock dramatically affects the value. Examine the following:

  • Function - If the clock functions well and can still keep time, it is worth more. It may be restored with antique clock parts by a clock restorer.
  • Wood condition - Cracks, crazing, and poor restoration jobs can detract from the value, while a wood case with a lovely patina can be worth more.
  • Clock face condition - If the clock face is still bright and readable, the clock is worth more. If it shows signs of restoration or rough use, it will detract.
  • Glass condition - Cracked and chipped glass takes away from the value, while glass in good condition is a plus.
Seth Thomas Clock

Compare With Recently Sold Clocks

Once you know as much as possible about your collectible mantel clock, take a look at recently sold examples for value. The key here is to ignore clocks that are still for sale. Sellers can ask any price they like for a clock, but that doesn't mean someone will pay it. Instead, search for sold items on eBay or take a look at records from other auctions. Here are a few examples of Seth Thomas mantel clocks and their sales prices:

Functional and Charming

An antique Seth Thomas mantel clock is more than a valuable collector item. It's also a functional part of your home, keeping time and offering vintage charm for your shelf or fireplace mantel.

Seth Thomas Antique Mantel Clocks Features and Values