Dr Ahmad K Elshennawy PhD, Mr George F Schrader
Published By: SME
A large proportion of industrial products are fabricated from metallic materials and machining is a common method of converting those materials into the required shape and size. In all metal machining operations an edged tool is driven through material to remove chips from the parent body and leave geometrically true surfaces. When metal is cut, the work piece surface is driven with respect to the tool, or the tool with respect to the surface, at a relatively high rate of speed. The most important part of a metal machining operation is the spot where the cutting tool meets the work piece and pries away chips. At production rates, metal is cut under extreme conditions. The tool exerts a tremendous pressure upon the chip. The metal cutting conditions include the cutting speed, the feed rate, rake angle of the tool, wear factor, vibration, and chatter. Metal-cutting tools may be classified as single point and multiple-point tools. Cutting-tool materials may be roughly classified into three categories: (1) the solid ferrous and nonferrous tool materials, (2) the hard insert materials and, (3) the super hard insert materials. Fluids are commonly applied to metal-cutting operations, chiefly to cool the tool and work piece and provide lubrication.
By Mark Hamel