Dormer PrametUnit 4 Lindrick Way S43 4XE Barlborough, Chesterfield, United KingdomT: 0870 850 4466F: 0870 850 8866
In conventional milling, also called up milling, the maximum chip thickness is at the end of the cut. The feed movement is opposite to the tool rotation.
Remember, the pre-drilling sizes for fluteless taps are different to those for conventional thread cutting taps. During the drilling operation, always ensure that work hardening of the component material is kept to a minimum.
Select the most appropriate drill for the application, bearing in mind the material to be machined, the capability of the machine tool and the coolant to be used.
Where possible, hold the tap in a good quality torque limiting tapping attachment, which ensures free axial movement of the tap and presents it squarely to the hole. It also protects the tap from breakage if accidentally 'bottomed' in a blind hole.
When regrinding a drill, always make sure that the correct point geometry is produced and that any wear has been removed.
The characteristic feature of the milling process is that each milling cutter tooth removes its share of the stock in the form of small individual chips.
Select the correct design of tap for the component material and type of hole, i.e. through or blind, from the Application Material Groups chart.
Tool holding is an important aspect of the drilling operation. The drill cannot be allowed to slip or move in the tool holder.
Ensure the component is securely clamped - lateral movement may cause tap breakage or poor quality threads.
Flexibility within the component and machine tool spindle can cause damage to the drill as well as the component and machine - ensure maximum stability at all times. This can be improved by selecting the shortest possible drill for the application.
