Last updated on November 6, 2024
Manufacturing watch cases was one of the hardest tasks to mechanise or automate. In the nineteenth century, automatic machinery enabled the mass production of watch movement parts. However, case making remained a largely manual craft skill. This was due to watch cases typically being made from precious metals like silver or gold. The amount of metal used for each case had to be minimised. Manual labour proved to be the most effective way to reduce waste and remain cost-effective.
In Britain, gold and silver items must be hallmarked before sale. An item cannot be submitted for hallmarking at a British assay office without a sponsor’s mark. This mark indicates who is responsible for the submission. In watch cases, the sponsor’s mark identifies the company that ordered or manufactured the case. Watch case makers employed various specialised craftsmen. The sponsor’s mark was entered by the business owner or a principal. It is usually unclear if they were involved in making the watch cases or if they were acting as an agent.
By the 19th century, watch cases were crafted in specialised workshops equipped with the necessary tools and machines. These included lathes, draw benches, rounds and weights, and hearths for annealing and heating soldering irons. While steam power was available in some larger factories, most English gold and silver watch cases were produced in small, non-powered workshops. Electricity was not available, instead, gas lamps provided lighting and human labour supplied the power. The manually operated “pole lathes” used for turning had existed for centuries. A flexible pole fixed to the floor near the lathe’s head held a rope that wrapped around a pulley behind the chuck, with the lower end attached to a foot pedal. Pressing the pedal would draw the rope down, spinning the work in one direction, and releasing it would cause the work to spin the other way as the bow pulled the rope upward.
To produce watch cases efficiently, the work was broken down into specialist areas:
Case maker: Formed, soldered, and turned the main parts of the case.
Joint maker: Crafted the joints (hinges) of the case.
Pendant maker: Created the pendant that supports the bow.
Bow maker: Manufactured the bow and bow screw.
Springer: Made and fitted the springs that open the case.
Engine turner: Engraved geometric patterns using a rose engine lathe, a specialized ornamental lathe used in watchmaking and jewellery for intricate designs.
Polisher: Polished the case and corrected marks left by hallmarking.
Bows and pendants were sometimes manufactured separately and in much greater numbers than the cases themselves. This is because the bow and the pendant were the parts of the case that were most likely to wear out and therefore there was increased demand from the watch repair trade.
Watch cases were crafted from sheet and bar materials, shaped and turned to precise dimensions and cross-sections before being soldered together. Creating these cases required at least three grades of solder, each with a different melting point, to ensure that multiple soldered joints could be performed without disturbing previous joints. Constructing a hunter case, for instance, could involve as many as 50 soldering steps. The hinges on watch cases, known as “joints,” demanded exceptional skill to fabricate. To create the knuckles of these joints, tubes were first formed from sheets, rolled, and then reduced in size by drawing them through progressively smaller holes in a draw-plate on a drawbench. Grooves were carefully filed into the parts to be joined, such as the middle of the case and the back, where small segments of tubing were soldered into each groove to form the knuckles. Since the positioning of these knuckles couldn’t be adjusted after soldering, precision was essential on the first attempt.
The joint pin is made of steel and may be shorter than the joint itself. This allows the ends to be plugged with the same metal as the case. To remove the pin, first remove the plugs, for example by using a graver. (A graver is a small, sharp, hand-held engraving tool used by watchmakers to cut, shape, or carve metal surfaces). By convention, insert the pin from the right when the case’s middle part faces away from you. Push it out from the left to remove it. The same insertion method applies to the joint that secures the movement to the case in a bolt-and-joint fitting.
In the later 19th century, watch case makers, such as the Dennison Watch Case Company, began using machinery to make the cases. In most factories, a steam engine on the ground floor or basement powered the machinery. A machine stamped blanks for case parts from gold or silver strips at twenty per minute. These blanks were then die-pressed into the back, bezel, and middle parts of the case, shaping the joint beds and thumb pieces simultaneously. Another machine refined the middle case part, adding knurling to the band. Finally, an additional machine created the case joints at a rate of around twelve per minute.
Types of watch case
Watches are traditionally divided into two broad categories: called hunter or open face, which in Swiss French are called, savonnette or Lépine. The terms hunter and open face, refer to both a type of case and also the layout of a movement. A hunter-cased pocket watch has a lid to protect the crystal and the dial. It is designed to be held with the pendant horizontal so that the thumb of the right hand can be used to press the crown itself to release an internal catch to open the protective lid so the time can be read.
A variation of the hunter case is the half hunter, which has a small glass window that allows the time to be read without opening the lid. Open-face watches have no lid over the crystal or dial. The watch is laid out so that the pendant and crown are at 12 o’clock and the small seconds is at 6 o’clock. An open-face pocket watch is designed to be held with the pendant vertical at the top.
When wristwatches were first designed, the 12 o’clock position was placed at the top for easy viewing on the wrist. The upper part of the strap would attach via lugs at the 12 and 6 o’clock positions. It was convenient to position the crown at 3 o’clock and the small seconds at 6 o’clock. This layout required using a hunter movement. The primary purpose of a wristwatch was to make time reading simple. If the watch case had a lid, it posed challenges. One needed to use the other hand to open it, or a demi hunter lid would hinder reading accuracy. From the beginning, it was clear that the most practical design for a wristwatch had to be open-face. Therefore, the logical wristwatch design involved fitting a hunter layout movement into an open-face case.
Pair cases
A pair case is an older type of case that began to appear around 1630. Early pocket watches, especially verge fusee watches, often used “pair cases”, two distinct cases, one nested inside the other. The inner case, or “box” (from the French term boîte), holds the movement, while the outer case is simply called the “case”.
The outer case’s main purpose was to cover a hole in the inner box. This hole allowed a key to be inserted for winding the watch. The box is bowl-shaped to secure the movement and includes a hinged bezel holding the crystal. The hinge, or “joint,” is at 12 o’clock, with a spring-loaded “bolt” catch at 6 o’clock. Pressing the bolt lets the movement swing out from the front.
Some watches had a third, protective outer case, often leather, to guard against wear and tear on the decorated case beneath. Keyless winding in the 19th century made these extra cases less necessary. However, a dust cover, or “cuvette,” was often included to keep the movement safe.
Crown types
A watch crown is the small, often ridged knob located on the side of a watch case, typically at the 12 or 3 o’clock positions. It’s primarily used to set the time and to wind the movement in mechanical watches. It is called the “couronne” in Swiss/French, which is crown in English. In vintage watches, the crowns were typically Onion or Pumpkin shaped. An onion crown has a spherical shape with vertical grooves to grip, making it look like an onion. A pumpkin crown is similar to the onion crown but more flattened, like the shape of a pumpkin. The onion form is the older and sits neatly on the pendants of pocket watches. The flatter pumpkin crown is more suited to wristwatches, such as the trench watches of World War 1.
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