Machine shop math: Common formulas, strategies

One of the more common problems I have seen in my years in the machine shop is a general lack of readily available and handy information on machine shop math, specifically on feeds, speeds and related formulae, writes Kevin Mulhern. "Whether you are programming a 5-axis CNC machine or turning handles on a 60-year-old knee mill, the numbers don't lie. However, one very important lesson I have learned is to respect the variables."