Barrel Hook
A hook in the barrel to which the mainspring is attached. The mainspring is sometimes attached by means of a hook on the spring which fit in a hole in the barrel.
How to true a balance, repair a chipped dial, temper a spring or test a stone — the working bench-book of the American watch trade, arranged A to Z.
A hook in the barrel to which the mainspring is attached. The mainspring is sometimes attached by means of a hook on the spring which fit in a hole in the barrel.