Page:Practical Treatise on Milling and Milling Machines.djvu/214

208 Drilling Holes in Bushing

A method of drilling holes in round pieces of work where they are required to be exactly spaced is shown in this operation.

The bushing is held in the spiral head chuck and is indexed in the regular way, or with the rapid index plate, if the number of holes required can be obtained by the latter.

An ordinary twist drill, held in a spring chuck, is employed and the table is usually fed by hand. A collet can be employed for a drill having a taper shank.