RPM Calculation for Gun Drilling: Formula and Examples
Calculating spindle speed for gun drilling is the same as for any turning operation. Get this wrong and you will burn up your tool or leave a terrible surface finish. I run these calculations before every job, and after enough setups the numbers become second nature. Here is how I do it. The RPM Formula and How I Use It The standard formula for spindle speed is: RPM = (Cutting Speed x 1000) / (Pi x Diameter) ...