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THE STUD (HAIRSPRING STUD)

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1. General description

It is the element that connects the Hairspring (balance spring) to the Balance cock (Figure 1). Generally made of Brass, the stud takes different forms depending on the construction. Generally, it consists of a mostly cylindrical part that is drilled or slotted. The hole or slot allows the outer end of the hairspring to be housed, secured with a brass pin, glued, or riveted. The upper part is fitted with a guide mark to ensure proper angular positioning when attached to the balance cock. Depending on the design choices of the Regulating organ, the stud is either housed directly in the balance cock, or held by an optional element of the Regulator assembly: the movable stud holder (Figure 2). This latter can be fixed or movable to allow for Regulation / Adjustmentof easier guide mark positioning.

Figure 1

Exploded view of the regulating organ

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Figure 2

Movable stud holder

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2. Classic pinned stud

The outer end of the Hairspring (balance spring) is engaged in a hole that passes through the stud. The hairspring is held firmly there by a pin made of Brass conical. This type of fastening allows the position of the stud on the terminal curve of the hairspring to be adjusted at any time (Figure 3).

Figure 3

Pinned stud

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3. Glued stud

The outer end of the hairspring is inserted through a notch made under the stud and is glued there. This is a common solution for mass-produced watches (Figure 4).

Figure 4

Glued stud

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4. “Geneva” Stud (hairspring stud)

The Geneva stud equips high-quality watches. It is intended for both flat hairsprings and hairsprings with terminal curves of the Breguet or Philips type. Like the classic stud, the hairspring is fixed there by a brass pin. Unlike the studs described previously, the Geneva stud is not adjustable in height. The construction of the regulation and the terminal curve must therefore be perfectly executed. Such studs can be directly integrated into the Balance cock (fixed stud) or on a movable stud holder (Figure 5).

Figure 5

“Geneva” Stud (hairspring stud)

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5. Handcrafted manufacture of a stud

The Stud (hairspring stud) is a component that is easy to manufacture regardless of its design. It is the design of the latter that will determine the tools and steps necessary for its manufacture. In any case, this will be simple and the usual tools of the Horologist (watchmaker) will allow its manufacture.

6. Industrial production of a Stud (hairspring stud)

The Stud (hairspring stud) is a component that is easy to manufacture. A few operations of Profile turning (turning, drilling, Milling) are enough and involve a manufacturing cycle of only a few seconds.