How To Identify Your Model 5

Plate Finish

The first step in determining your grade is to figure out which plate finish you have.

Setting Mechanism

Step Two in defining your grade is knowing the method of setting the hands, so remove the bezel and look for a setting lever. If there isn't one, then your watch is pendant-set.

Jewel Count

Another step is the jewel count, which came in a wide range. Not all of them are marked.

See The Counts

Adjustments

Some weren't adjusted, some were adjusted, some were adjusted to 3, 5 or 6 positions, and others adjusted to positions and temperature. All adjusted variants were clearly marked.

Regulators

Regulators were both inboard and outboard, simple or with a micro-adjustment screw.

See Them All

Hairsprings

Nearly every grade of the Model 5 came equipped with Breguet (overcoil) hairsprings. The only exceptions were the 11-jewel gilt Grade 58 and the 11-jewel nickel Grade 158.

The Model 5 Jeweling

Jeweling Locations

Use this page to visually compare your Model 5 Seth Thomas against these examples, paying attention to which positions have jewels and which ones have bushings. There are only seven possible locations:

The mainspring barrel, which provides power
The center (second) wheel, which drives the hands
The third wheel between the center and fourth wheels
The fourth wheel, which holds the seconds hand
The escape wheel, always with an odd number of teeth
The pallet fork with entry and exit stones
The balance wheel, which carries the roller jewel

The Model 5 Counts

7-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones (1 entry and 1 exit)
1 roller jewel

The entire gear train has metal bushings.

All jewels are on the balance assembly.

Grades 47 and 57 only.

11-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 hole jewel for the pallet staff, the escape wheel, and the 3rd and 4th wheels, for a total of four

Press-fit jewels only on the upper plate.

15-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet staff and the escape, 3rd, and 4th wheels, for a total of eight

Note that the count isn't marked and that the center wheel has a bushing and not a jewel.

17-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet and the escape, 3rd, 4th, and center wheels, for a total of ten

The earliest variants were not marked. Note that the center wheel now has jewels.

21-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet and the escape, 3rd, 4th, and center wheels, for a total of ten
1 pair of cap jewels for the pallet arbor and the escape wheel, for a total of four

23-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet and the escape, 3rd, 4th, and center wheels, for a total of ten
1 pair of caps for the pallet and escape wheel, and 1 each on the upper 3rd and 4th wheels, for a total of six

24-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet and the escape, 3rd, 4th, and center wheels, for a total of ten
1 pair of caps for the pallet arbor, escape and 3rd wheel, and 1 on the 4th wheel, for a total of seven

25-Jewel

2 balance staff hole jewels
2 balance staff cap jewels
2 pallet stones
1 roller jewel
1 pair of hole jewels for the pallet and the escape, 3rd, 4th, and center wheels, for a total of ten
1 pair of cap jewels for the pallet arbor, escape and 3rd wheels, and one on the upper 4th wheel for a total of seven
1 hole jewel for the upper mainspring barrel

Other Counts

Were there more jewel counts? Yes, there were some one-off counts in the Model 5:

The 19-jewel Grade 262
The 22-jewel Maiden Lane
The 28-jewel Railway

None of these counts made it into regular production. All three of them are laid out in detail in different sections of the Model 5 page.