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HAND-FITTING LEVERS

“Presto” hand-removing tool

What are hand-fitting levers used for?

Hand-fitting levers form a family of tools specifically designed for removing the Hands of a watch, that is, for separating them from the cylindrical supports fitted with a tight friction fit that secure them to the Motion work — cannon pinion, hour wheel and, where applicable, small seconds axis. Their design meets a very constrained set of specifications: exert strictly axial traction on the hand, without applying any lateral load likely to damage the pivots, while preserving the underlying dial and avoiding any deformation of the hand itself.

In its most traditional form, the hand-fitting lever consists of two thin metal rods flattened at their tip and ending in a notch or spearhead shape designed to engage beneath the hand’s hub on either side of the central tube. The horologist (watchmaker) holds the two rods between their fingers, carefully positions them beneath the hand, then applies an upward levering motion, resting against the dial previously protected by a cardboard or plastic mask. The symmetrical action of the two rods converts the manual gesture into perfectly axial traction, an essential condition for preserving the component and its bearings.

A more recent and widely used variant, known as “presto” — named after the most common tool available on the market — takes the form of a spring clamp fitted with two spearhead jaws and, most often, a protective plate made of soft material or Polished Metal that is placed between the Hand and the Dial before the action is carried out. Pressing the clamp triggers a spring-loaded mechanism that forces the jaws under the Hand while pushing the plate against the Dial: removal is achieved in a single motion, with high repeatability and no risk to the External parts (case, dial, hands).

At the Bench, the Horologist (watchmaker) proceeds with the successive removal of the Hands in the usual order — first the seconds Hand, then the minutes Hand, and finally the hours Hand — systematically interposing, between the Hand and the Dial, a thin film or a protective paper when the presto is not equipped with one. The reverse operation — fitting the Hands — does not involve these levers, but rather a specific hand-remover or a Hand-fitting stake, which exert a downward pressure. Although seemingly modest, the Hand-fitting levers are among the most delicate tools to handle at the workstation: a poorly controlled movement, and the Hand becomes deformed, the Dial gets scratched, or the pivots of the Motion work are put under strain.