Practical Balance and Hair-Spring Work

Written in 1925, Practical Balance and Hair-Spring Work is Walter J. Kleinlein’s bench-level companion to his earlier Rules and Practice for Adjusting Watches (1920). Where the earlier book lays out the theory of temperature, isochronism, and positional adjustment, this one drills into the manual operations that make those adjustments possible.

Across fourteen chapters Kleinlein walks through the full balance-and-hairspring workflow: equipping the bench; truing the balance wheel in the flat and in the round; correcting eccentric pivots, short-arm balances, and the effect of temperature on truing; selecting and fitting screws; poising on calipers and on the poising tool; vibrating and timing hairsprings; truing and colleting hairsprings; and applying the Breguet overcoil. Each operation is described as he taught it to apprentices, with the tools to use, the order to use them in, and the slight errors to watch for.

A methodical guide to the regulating organ of the mechanical watch, written for the working bench. Anyone restoring high-grade American pocket movements—Hamilton, Waltham, Illinois, Hampden—will find Kleinlein’s procedures still directly applicable.