1904 Seth Thomas Watch Material

Models 2, 3, and 4
Models 16, 17, and 18
Model No. 5
Seth Thomas Dials
Serial Number Chart
Eagle Series
Seth Thomas Hands
Century Series
Companion
Introduction
Model No. 14
Model No. 1
Model No. 15
List of Models
Seth Thomas Watch Material 1904 Catalog No. 650
Seth Thomas Clock Company 1892-1893 Illustrated Catalogue No. 531
Seth Thomas Clock Company 1909-1910 Catalogue No. 675
Records, Research & Sources
Sizes and Models, Winding and Setting
Seth Thomas Pocket Watch Dials
Seth Thomas Pocket Watch Hands
A.C. Becken
Brooks Optical Co.
C.H. Knights
Holsman and Alter
J.H. Purdy
J.M. Smyth and Co.
Montgomery Ward
Lapp and Flershem
Butler Brothers
Sears, Roebuck Co.
Seth Thomas
S.F. Myers
N. Shure
Roy Ehrhardt
Pocket Watch Database

Model No. 1

Page 2 of the 1904 Watch Material Catalog illustrates the 18-size 3/4 plate Seth Thomas Model 1 gilt movement with 11 jewels. Below are twenty numbered mechanical components identifying individual parts used in the construction and repair of Model 1.
Page 3 of the 1904 Watch Material Catalog. The "Notes" section of the page is historically significant because it documents early factory terminology component organization, movement specifications, winding and setting configurations, etc.

Pages 2 and 3 of the 1904 Seth Thomas Watch Material catalog illustrate the 18-size ¾ plate Seth Thomas Model 1 gilt movement with 11 jewels. Beneath the movement illustration are twenty numbered mechanical components identifying individual parts used in the construction and repair of the Model 1 movement. The “NOTES” sections of the pages are historically significant because they document early factory terminology, component organization, movement specifications, winding and setting configurations, and technical data related to the Model 1 during the formative years of Seth Thomas watch production.

This material from the Seth Thomas Pocket Watch Mainsprings page re-presented below was extracted from the 1904 Seth Thomas Watch Material Catalog and that data was expanded upon by acquiring replacement mainsprings and catalogs manufactured by more than a dozen aftermarket manufacturers. This presentation demonstrates the ability to glean very valuable information from the 1904 Seth Thomas Watch Material Catalog and very effectively and materially expand upon it with additional research to rebuild the original dataset lost in the disastrous August 1955 flood that devastated the Seth Thomas factories in Connecticut.

Alternative Manufacturers of Mainsprings for Seth Thomas Pocket Watches

In addition to original Seth Thomas mainsprings, replacement mainsprings for Seth Thomas pocket watches were also offered by other manufacturers and material suppliers. The examples below document alternative manufacturers, package numbers, stated Seth Thomas applications, and any measurements printed on the original packaging. The metric units used on the packaging are confusing when trying to compare and cross-reference the mainsprings. For the purpose of clarity, the metric units used on the Mainspring Cross-Reference Chart below for the mainspring lengths have all been expressed in centimeters and the metric units used for mainspring width and thickness have all been expressed in millimeters regardless of how they were expressed on the packaging.

H R Alloy, Nu Vigor, and Sandsteel replacement mainspring packaging and catalogs identify Seth Thomas 16-size and 12-size applications using the same respective numbers, 2106 and 2521. These entries are listed as inferred Seth Thomas factory part numbers because they are not currently documented in surviving Seth Thomas material catalogs reviewed for this project.

Seth Thomas Pocket Watch Mainspring Cross-Reference
Manufacturer Mfr. Part No. ST Application Factory Part No. Length Width Thickness Dennison Details
Original Seth Thomas / 1904 Watch Material Catalog No. 650
Seth Thomas 23 Model 1 23 21.5 inches .132 .0075 24 wide, 3 thick Mainspring with patent brace.
Seth Thomas 140 Model 2, Model 3, and Model 4 140 21.5 inches .132 .0075 24 wide, 3 thick 1st QUALITY; with patent brace.
Seth Thomas 141 Model 2, Model 3, and Model 4 141 20 inches .132 .009 24 wide, 1¼ thick 2nd QUALITY.
Seth Thomas 339 Model 5 339 21.5 inches .132 .0075 24 wide, 3 thick With patent brace. Catalog note states movements Nos. 300,000 to 350,000 are 7 jewels and use the same mainspring, yoke, yoke screw, and setting arm as Model 6.
Seth Thomas 436 Model 5 High Grade Railroad Movements 436 21.5 inches .132 .0075 24 wide, 3 thick EXTRA QUALITY.
Seth Thomas 536 Model 6 and Model 7 Eagle Series Old Model 536 20 inches .132 .009 24 wide, 1¼ thick With patent brace.
Seth Thomas 633 Model 8 and Model 9 Eagle Series New Model 633 20 inches .116 .009 20 wide, 1¼ thick With patent brace.
Seth Thomas 729 Model 10 and Model 11 Century Old Model 729 20 inches .132 .009 24 wide, 1¼ thick With patent brace.
Seth Thomas 828 Model 12 and Model 13 Century New Model 828 20 inches .116 .009 20 wide, 1¼ thick With patent brace.
Seth Thomas 927 Model 14 927 17 inches .076 .0065 10 wide, 4½ thick With patent brace.
Seth Thomas 1026 Model 15 1026 17 inches .076 .0075 10 wide, 3 thick With patent brace.
Seth Thomas 1026 Model 16 1026 17 inches .076 .0075 10 wide, 3 thick With patent brace.
Seth Thomas 1026 Model 17 1026 17 inches .076 .0075 10 wide, 3 thick With patent brace.
Seth Thomas 1119 Model 18 1119 17 inches .076 .0075 10 wide, 3 thick With patent brace.
Inferred Seth Thomas Factory Part Nos. from Alternate Manufacturers' Retail Packaging or Catalogs
Seth Thomas 536 ST 18-size 536 not stated 3.30 mm 0.195 thick 24 wide, 3 3/4 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 729 ST 18-size 729 not stated 3.30 mm 0.225 thick 24 wide, 1 1/2 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 828 ST 18-size 828 not stated 2.90 mm 0.225 thick 20 wide, 1 1/2 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 927 ST 6-size 927 not stated 1.90 mm 0.16 thick 10 wide, 6 1/2 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 1026 ST 6-size 1026 not stated 1.90 mm 0.195 thick 10 wide, 3 3/4 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 1441 ST 0-size 1441 not stated 1.50 mm 0.15 thick 6 wide, 7 thick From 1944 Sandsteel Catalog No. 12
Seth Thomas 2106 Model 21 2106 21 inches 2.35 mm 0.23 mm 14 1/2 wide, 1 thick 16-Size
Seth Thomas 2521 Model 22 or 23 2521 21 inches 1.95 mm 0.205 mm 10 1/2 wide, 3 thick 12-Size
Original Seth Thomas Package Example
Seth Thomas not stated ST 12-size not stated not stated not stated not stated not stated .234 as marked on original package.
Alternative Manufacturers and Material Suppliers
Black Shield 4397 ST 18-size No. 536 No. 536 20 1/4 inches / 51.10 cm 3.30 mm 0.195 thick 24 wide, 3 1/4 thick Swartchild & Co., Chicago.
Black Shield 4398 ST 18-size No. 729 Century Wide No. 729 20 1/4 inches / 51.10 cm 3.30 mm 0.225 thick 24 wide, 1 1/2 thick Swartchild & Co. Catalog No. 76
Black Shield 4399 ST 18-size No. 828 Century Narrow No. 828 20 1/4 inches / 51.10 cm 2.90 mm 0.225 thick 20 wide, 1 1/2 thick Swartchild & Co. Catalog No. 76
Black Shield 18978 ST 16-size No. 2106 Centennial No. 2106 20 inches / 50.25 cm 2.40 mm 0.23 thick 15 wide, 1 thick Swartchild & Co. Catalog No. 76
Black Shield 4399A ST 12-size New Model not stated 20 1/2 inches / 52.00 cm 2.00 mm 0.20 thick 11 wide, 3 1/2 thick Swartchild & Co. Catalog No. 76
Black Shield 4400 ST 6-size Century No. 1026 14 inches / 35.50 cm 1.90 mm 0.195 thick 10 wide, 3 3/4 thick Swartchild & Co. Catalog No. 76
Charles Robert 701 ST 18-size No. 536 not stated 3.30 mm 0.185 thick 24 wide, 4½ thick Swiss Made
Charles Robert 705 ST 12-size not stated not stated not stated 0.205 not stated Swiss Made
Charles Robert 706 ST 6-size No. 1026 not stated 1.9mm 0.205 thick 10 wide, 3 thick Swiss Made
Diamond 76 Model 1 23 not stated not stated not stated not stated Benj. Allen & Co.
Diamond 149 Model 3 140 / 141 not stated not stated not stated not stated Same as Diamond Part No. 76, Benj. Allen & Co.
Diamond 220 Model 2 140 / 141 not stated not stated not stated not stated Same as Diamond Part No. 76, Benj. Allen & Co.
Diamond 271 Model 4 140 / 141 not stated not stated not stated not stated Same as Diamond Part No. 76, Benj. Allen & Co.
E. & J. Swigart Co. A 1175 ST 18-size No. 828 not stated 2.90 mm 0.225 thick 20 wide, 1½ thick All Jewels
E. & J. Swigart Co. 702 ST 18-size 18-size All Models 20 1/2 inches 3.30 mm 0.22 thick 24 wide, 2 thick Illustrated Manual of American Watch Movements, SETH THOMAS and CENTURY
E. & J. Swigart Co. 703 ST 18-size 18-size All Models 20 1/2 inches 2.90 mm 0.22 thick 24 wide, 2 thick Illustrated Manual of American Watch Movements, SETH THOMAS and CENTURY
E. & J. Swigart Co. 704 ST 16-size 16-size All Models 18 1/2 inches 2.40 mm 0.23 thick 15 wide, 1 thick Illustrated Manual of American Watch Movements, SETH THOMAS and CENTURY
E. & J. Swigart Co. 705 ST 12-size 12-size All Models 16 1/2 inches 2.00 mm 0.21 thick 11 wide, 3 thick Illustrated Manual of American Watch Movements, SETH THOMAS and CENTURY
E. & J. Swigart Co. 707 ST 6-size 6-size All Models 14 1/2 inches 1.90 mm 0.15 thick 10 wide, 7 thick Illustrated Manual of American Watch Movements, SETH THOMAS and CENTURY
Etiquette Inc. 520 ST 18-size No. 536 54.50 cm / 21½ inches 3.30 mm 0.19 thick 24 wide, 4½ thick Made by Gruen Watch Company in Switzerland
The Fulton Wine Color ST 18-size not stated not stated not stated 0.19 thick not stated No Retaining Clamp
HR Alloy SA 652 ST 18-size No. 536 T Brace 21½ inches 3.30 mm 0.19 thick 24 wide, 2 thick No Retaining Clamp
HR Alloy SA 653 ST 18-size No. 729 T Brace 30 inches 3.30 mm 0.22 thick 24 wide, 2 thick By Hammel, Riglander & Co. of Generale Ressorts in Switzerland
HR Alloy A 654 ST 16-size No. 2106 21 inches 2.35 mm 0.23 thick 14 1/2 wide, 1 thick Made in Switzerland.
HR Alloy SA 655 ST 12-size No. 2521 21 inches 1.95 mm 0.205 thick 10 1/2 wide, 3 thick Made in Switzerland.
KBK 3033 ST 16-size T end not stated not stated 2.34 mm 0.22 thick 15 wide, 2 thick Kilb, Beck, Kuesel, Inc.
Marco 1001 ST 18-size New Style No. 536 20 1/4 inches not stated not stated 24 wide, 3 3/4 thick not stated
Marco 1002 ST 18-size Century, wider Factory No. 729 No. 729 not stated not stated not stated not stated not stated
Marco 1010 ST 16-size No. ___ not stated not stated not stated not stated Made in Switzerland.
Marco 1030 ST 12-size T end not stated not stated not stated not stated not stated Made in Switzerland.
Nu Vigor 1072 ST 18-size No. 141 53.34 cm / 21 inches 3.30 mm 0.22 thick 24 wide, 2 thick Made in Switzerland.
Nu Vigor 1073 ST 18-size No. 536 53.98 cm / 21 1/4 inches 3.30 mm 0.195 thick 24 wide, 3 3/4 thick, 21 1/4 long Made in Switzerland.
Nu Vigor 1074 ST 18-size No. 729 50.80 cm / 20 inches 3.30 mm 0.22 thick 24 wide, 1 1/2 thick Made in Switzerland.
Nu Vigor 1075 ST 18-size No. 828 50.80 cm / 20 inches 2.90 mm 0.22 thick 20 wide, 2 thick Made in Switzerland.
Nu Vigor 1076 ST 16-size No. 2106 53.34 cm / 21 inches 2.40 mm 0.22 thick 14 1/2 wide, 2 thick Nu Vigor Catalog
Nu Vigor 1077 ST 12-size No. 2521 53.34 cm / 21 inches 2.00 mm 0.20 thick 11 wide, 3 1/2 thick Nu Vigor Catalog
Nu Vigor 1078 ST 6-size No. 1026 36.20 cm / 14 1/4 inches 1.90 mm 0.195 thick 10 wide, 3 3/4 thick Nu Vigor Catalog
Sandsteel 536 ST 18-size No. 536 not stated 3.30 mm 0.195 thick 24 wide, 3 3/4 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 729 ST 18-size No. 729 not stated 3.30 mm 0.225 thick 24 wide, 1 1/2 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 828 ST 18-size No. 828 not stated 2.90 mm 0.225 thick 20 wide, 1 1/2 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 927 ST 6-size No. 927 not stated 1.90 mm 0.16 thick 10 wide, 6 1/2 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 1026 ST 6-size No. 1026 not stated 1.90 mm 0.195 thick 10 wide, 3 3/4 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 1441 ST 0-size No. 1441 not stated 1.50 mm 0.15 thick 6 wide, 7 thick From 1944 Sandsteel Catalog No. 12
Sandsteel 2106 ST 16-size No. 2106 not stated 2.40 mm 0.22 thick 15 wide, 2 thick Made in U.S.A. by the Sandsteel Spring Division of Sandvik Steel, Inc. aka Watch-Motor Mainspring Co. Inc. New York
Sandsteel 2521 ST 12-size No. 2521 not stated 2.00 mm 0.20 thick 11 wide, 3 1/2 thick Made in U.S.A. by Watch-Motor Mainspring Co. Inc. New York
Unit Resilient 1002 ST 18-size Century not stated not stated not stated 0.22 thick not stated not stated
Unit Resilient not stated ST 6-size not stated not stated not stated 0.15 thick not stated Made by Waltham Watch Company Waltham, USA
U.S.R. not stated ST 18-size Old Style No. 23 not stated not stated not stated not stated By Ulysse Sandoz-Robert of La Chaux-de-Fonds, Switzerland
U.S.R. not stated ST 18-size No. 536 No. 536 not stated not stated not stated not stated not stated
U.S.R. not stated ST 18-size No. 828 Century New Model No. 828 not stated not stated not stated not stated Photos contributed by Seth R. Thomas III
U.S.R. not stated ST 12-size not stated not stated not stated not stated not stated not stated

View a printable PDF version of the Seth Thomas Mainspring Cross-Reference Chart

References/Bibliography