Shock resistant watch

Shock resistant is a common mark stamped on the back of wrist watches to indicate how well a watch copes with mechanical shocks. In a mechanical watch, it indicates that the delicate pivots that hold the balance wheel are mounted in a spring suspension system intended to protect them from damage if the watch is dropped. One of the earliest and most widely used was the Incabloc system, invented in 1934. Before the widespread adoption of shock resistant balance pivots in the 1950s, broken balance wheel staffs were a common cause of watch repairs.

Usage

Virtually all mechanical watches produced today are shock resistant. Even divers' watches (according to ISO 6425) must correspond not only with such criteria as water resistance, luminosity, magnetic resistance and strap solidity, but also shock resistance.

ISO 1413 shock-resistant standard

The International Organization for Standardization issued a standard for shock resistant watches, which many countries have adopted. ISO 1413 Horology—Shock-resistant watches specifies the minimum requirements and describes the corresponding method of test. It is intended to allow homologation tests rather than the individual control of all watches of a production batch. It is based on the simulation of the shock received by a watch on falling accidentally from a height of 1 m on to a horizontal hardwood surface.