
Category: American Clock Mainsprings
Many American antique clocks had mainsprings that were too strong when they were new. For many years, the so called “standard” mainspring size was 3/4″ by .018″ by 96″, and new mainsprings of this size will cause wear to the mainwheel teeth. In this section I give examples of better mainsprings to use for new replacements. It is best to keep the original old mainsprings in some cases, and I give examples of this, too.


A New Mainspring for Seth Thomas No. 89 and Other American Clock Movements

Ansonia Black Iron Mantel Clock

Ansonia La Layon Royal Bonn Porcelain China Mantel Clock

Gilbert Tambour Mantel Clock with Bim-Bam Hour Strike

Seth Thomas Sentinel No. 4 Tambour Mantel Clock

Seth Thomas Small Mahogany Adamantine Mantel Clock

Seth Thomas Beehive Mantel Chime Clock with No. 124 Movement

Seth Thomas Tambour Clock with Quarter Hour Strike, 1939

Gilbert 8-Day Cottage Clock

Plymouth by Seth Thomas Round Top Mantel Clock, 1940

Waterbury “Admiral” 30-Day Round Drop Oak Cased Wall Clock

Jahresuhrenfabrik (JUF) 400 Day Clock ca. 1912 with Disc Pendulum

Seth Thomas Adamantine Mantel Clock, 1895, Beautiful Tan with Deep Red and Orange Swirls

Seth Thomas Adamantine Mantel Clock with 89C Movement

Ansonia “Burton” Oak Kitchen or Shelf Clock

Gilbert “Consort” Oak Long Drop Octagon Wall Clock

Seth Thomas Adamantine Mantel Clock with Mainspring Broken in 22 Pieces!

Sessions Store Regulator Clock in Oak Case

Seth Thomas Rosewood Drop Octagon (Schoolhouse) Clock

Sessions Oak Cased Drop Octagon (Schoolhouse) Clock

E. N. Welch Hanging Oak Kitchen Clock

Sessions Black Mantel Clock, Early

New Haven Clyde Walnut Kitchen Clock, ca. 1885

Waterbury Niagara Oak Calendar Shelf Clock, ca. 1911

Seth Thomas Sentinel No. 19 Tambour Mantel Clock

Ansonia Enameled Iron Black Mantel Clock

Seth Thomas Adamantine Mantel Clock, 6 Half-Pillar, Black and Marbleized

1939 Plymouth (by Seth Thomas) Tambour Mantel Clock with Quarter Hour Strike
