Hole Production

Abstract

This seemingly simple operation is often overlooked in the general acclaim that is afforded to other more sophisticated aspects of engineering development. The need to produce a hole has been with us since man needed to make even the most simple tools from materials too hard to be pierced by hammering or burning; friction with an abrasive material using Archimedes’ drill action was probably the next progressive step. With the advent of metal the next step is a simple flat drill of the pointed or spade type. This being forged flat would need little alteration to twist the flat blade, producing as a result ‘flutes’, thus greatly assisting in the removal of debris from the hole being produced. From this, a mainly subjective view, developments over the years have produced many different drills with a very superior performance, economics being considered not only in drill price but as a ‘cost per hole’. When it is necessary to specify a drill to produce a desired hole size, it should be borne in mind that standard drills are available before a non-standard is chosen, or even to consider redesign of the component to use standard drills where possible.