Choosing cutting broaches

Many amateurs suffer from extreme lack of tools and cannot justify the purchase of specialist ones at the start. In particular, cutting broaches are hard to choose. You will need broaches to suit any bushes you fit.

Looking at bush size charts you will see many sharing the same outside diameters. For example, many have outside diameters of 4.50mm. Looking at a list of broaches, number 14 in the Stubbs gauge has a maximum working diameter of 4.57mm. This broach will enable you to fit this bush with ease.

Simply repeat this exercise for any bushes you expect to fit. Broaching the inside of new bushes will depend on the pivots themselves. You will need to buy several for your first clock, but as your range builds up, you will be able to bush almost anything from stock. The reason no one sells 'all the broaches you're likely to need' is because this depends on the kind of clocks you work on. Carriage clocks use a quite different range to longcase clocks.