The insert drill QTD had previously been available from 13 mm diameter. Responsible for this is i.a. in the cooling duct in the basic tool body. The smaller the basic tool body, the more the normal central coolant supply system impairs the performance of the tool.
The central coolant supply weakens the core of the drill and makes it unstable. Furthermore, the cooling ducts have to be made increasingly smaller. This results in a decreasing flow rate of the coolant to the cutting edge. Steel basic tool bodies with spiral cooling ducts that are common in solid carbide tools are not yet common in small diameters.
Laser sintering enables optimum cooling duct design
Laser sintering enables basic bodies in the diameter range from 9 to 12 mm with spiral cooling ducts to be produced by 3D printing. Compared with the central coolant supply with diversions, this design achieves a 100 % increased coolant flow rate, particularly thanks to the deviation from the circular cooling duct profile. The insert drill QTD for small diameter ranges has been registered for patent and is available as standard.