<P> If variables such as cutter geometry and the rigidity of the machine tool and its tooling setup could be ideally maximized (and reduced to negligible constants), then only a lack of power (that is, kilowatts or horsepower) available to the spindle would prevent the use of the maximum possible speeds and feeds for any given workpiece material and cutter material . Of course, in reality those other variables are dynamic and not negligible; but there is still a correlation between power available and feeds and speeds employed . In practice, lack of rigidity is usually the limiting constraint . </P> <P> The phrases "speeds and feeds" or "feeds and speeds" have sometimes been used metaphorically to refer to the execution details of a plan, which only skilled technicians (as opposed to designers or managers) would know . </P> <P> Cutting speed may be defined as the rate at the workpiece surface, irrespective of the machining operation used . A cutting speed for mild steel of 100 ft / min is the same whether it is the speed of the cutter passing over the workpiece, such as in a turning operation, or the speed of the cutter moving past a workpiece, such as in a milling operation . The cutting conditions will affect the value of this surface speed for mild steel . </P> <P> Schematically, speed at the workpiece surface can be thought of as the tangential speed at the tool - cutter interface, that is, how fast the material moves past the cutting edge of the tool, although "which surface to focus on" is a topic with several valid answers . In drilling and milling, the outside diameter of the tool is the widely agreed surface . In turning and boring, the surface can be defined on either side of the depth of cut, that is, either the starting surface or the ending surface, with neither definition being "wrong" as long as the people involved understand the difference . An experienced machinist summed this up succinctly as "the diameter I am turning from" versus "the diameter I am turning to ." He uses the "from", not the "to", and explains why, while acknowledging that some others do not . The logic of focusing on the largest diameter involved (OD of drill or end mill, starting diameter of turned workpiece) is that this is where the highest tangential speed is, with the most heat generation, which is the main driver of tool wear . </P>

What is the cutting speed for mild steel