Why does 4pvd provide so many different styles of fixtures?
The necessity for the fixture systems Nova, Colt and Sphere can easily be explained by use of examples like drills, mills, punches and taps. Taps usually require a thin but very constant film thickness along all the cutting edges. For this the axle of the taps is positioned parallel to the surface of the evaporators, and than rotated around the tool axle. This request is fulfilled by the colt fixtures Even though drills and mills can also be coated by use of the colt design, this way will not achieve the optimum film thickness distribution along the functional areas. If drills DIN 338 are coated in sphere fixtures with a tilt angle of 28, a ratio of coating thickness of 1:1 on the tip versus the diameter can be achieved. As a nice side effect, the number of pieces is higher for sphere fixtures, as the batch calculator proves. For micro drills, mills and punches with a short working area sometimes the coating thickness is only specified for a very small area around the tool tips. Now th
