"The making of things to a high measure of accuracy is not just a test of workmanship. It is a fundamental to service production. In such production there can be no fitting of parts in assemblies or in repairs. Every crankshaft must be exactly like any other crankshaft. Of course no two parts are ever absolutely alike, except by accident, for it does not pay to try for accuracy beyond a certain point. But any kind of a machine which has moving parts must be accurately made or there will be an amount of vibration through play that will shorten the life of the machine and also decrease its running efficiency."