OVERVIEW

In machines shops, the words 'speeds and feeds' are often associated with descriptions of any cutting conditions required to machine a part. This is not a correct approach to use a single description for a large number of possibilities, but there is a certain reason for it. In CNC work, speeds and feeds play such a dominant role in program development, that they often overshadow other - equally important - machining decisions. In addition to speeds and feeds, CNC programmer has to consider cutting tool and its capabilities, such as depth and width of cut, method of entry into the part, machining power and forces, etc. Machine manuals, tooling catalogues, text books, charts, internet, and many other resources, offser extensive range of speeds and feeds for various tools and materials, and how they work together. We can benefit from all of them.

The first thing to keep in mind is that there is no recipe, no one method or a single formula, that would point towards the one and only possible spindle speed or cutting feedrate for a particular job. It is just not possible. Speeds and feeds are a small, but important, part of a much larger subject - the total setup. Speeds and feeds are provided as a range of selections, from which the programmer selects the one most suitable. Large ranges do not offer much of a solution that novice programmers are seeking. Experienced programmers also use their own experience,...