End-milling cutters

The groove into which a key is fitted is referred to as a keyseat when referring to shafts and a key way when referring to hubs. Keyseating is the actual machine operation of producing keyseats. Keyways are normally made on a keyseater or by a broach. Keyseats are normally made with a rotary or end mill cutter. 

The effective key length, L is that portion of key having full bearing on hub and shaft. Note that the curved portion of the keyseat made with a rotary cutter does not provide full key bearing, so L does not include this distance. The use of an end mill cutter results in a square-ended keyseat. 

Recommended tools Single-bladed fly cutters or a two-fluted end mill cutter with 10°... 

Solid carbide drills, taps and end milling cutters are available for cutting a wide variety of materials. Some have a surface coating such as titanium aluminium nitride (TiAlN) which fiirther enhances cutting performance, offering different levels of surface hardness, thermal and frictional properties. 

Allhough the majority of end-milling cutters are manufactmed from HSS and HSCo, some with hard surface coatings, soUd carbide cutters are available, also with surface coatings which include titaniiun aliimin-ium nitride (TiAlN) to further enhance their cutting performance. 

Having centred the rotary table, consider the workpiece shown in Fig. 11.21, which requires the 40mm radius to be machined using an end-milling cutter in a vertical milling machine. 

Clamp the workpiece in position and mount the required size of end-mill cutter in the machine. 

Coated carbide tools are known to perform better than uncoated carbide tools. Thus commercially available CVD coated carbide tools were used in this investigation. The tools used were flat end mill cutters produced by WIDIA (EM-TiAlN). The tools were coated with TiAlN coating. For each material a new cutter of same specification was used. The details of the end milling cutters are given below ... 

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