OVERVIEW

A wide diversity of tools are in fact gathered under the words 'cutting tools', such as turning tools, drills, threading taps and dies, shaping, planing tools, scrappers, shaving tools and broaches, saws, milling cutters and hobs, counter bores and countersinks, reamers, files, grinding wheels. Summarised, the machining operation factors affecting the final part properties are:

• the part to be machined (workpiece - shape and material),

• the machine-tool, and the cutting tool [164].

Only an approach that includes the wide variety of workpieces which was described before also the different tool materials and geometries can bring in a broader view on complexity of machinability of PM materials. It was shown before that in some extent at increasing hardness of the PM material the increased wear of the cutting tool was noticed in general.

The productivity of machinery manufacturing industries has continually increased, in particular, from the dramatically increased cutting speeds chip removal rate enabled by the cutting tools. These performances are mainly linked to the study and developments of all types of cutting tools especially of hard and super hard materials.

There is a great variety of tools and materials in use in wrought steel machining which are applied in most cases with some modifications in geometry also in PM steel machining. The use of a specific cutting tool is depending on the workpiece material properties and the performance of the production units. General tendencies like dry machining, which is the special area in machining of PM materials, or hard...