ATA International Product Catalogue

220341 1501 We recommend for drilling depth of more than 4×D our 'Soft Inn' strategy. This drilling strategy supports the chip transport and enhance the product safety many times. No centering or pilot hole. This reduces your production time about 15% as well the storage costs about 50%. I. The run out with a drill in a spindle should be less than 0.002 mm. II. The shrink fit system acts as an effective holder. Selection of the appropriate means to achieve tension: The tension the drill requires is the cylinder shank seat in accordance with DIN 6535 Form HAK/HA. In addition to that high-precision true running and non-positive tensions show stress chuck and contraction chuck. With the tools having an optimum tension both high-precision true alignment and high quality surfaces can be achieved. In many cases there is therefore no need of friction operations. The eccentricity of revolving tools should not exceed 0.015 mm . Due to their geometrical layout and inherent stiffness the tools are qualified for drilling at maximum power. Working cycles such as precentring, pilot-drilling and boring open should not be carried out to avoid the rotational axis shifting to the pilot-drilling operation when the tools are put on. Furthermore, an unfavourable intervention of this bits with the point angle deviating to the pilot-drilling tool is avoided. Should chamfering be required, the chamfering is to be carried out after the drilling operation. The advance values should not be lower than those specified in the cut value chart to achieve a controlled chip breakage. When the chip centre cross-section is too small (advance is insufficient) an insufficient quantity of heat is carried off trough the chip. The temperature penetrates more and more into the tool, resulting in loss of toll life. In case of an interrupted cut, e.g. approach inclinations and emersion inclinations of transverse drillings reduced advance values should be applied in this area. The drills are to be operated with sufficient cool- ing lubrication. To achieve good working results, high-quality half synthetic or emulsion cooling lubricants (min. 10 oil) and EP additives are to be used. By that means a longer tool life as well as higher tolerance precisions and surface qualities can be achieved. Given more than 5 × D drilling depth chamfering is required once or repeatedly under unfavourable conditions. From 8 × D onwards the advance should be reduced by 50% when spot-drilling. Solid carbide drills with interior cooling require 40 - 50 bar cooling agent pressure to ensure an optimum of chip flow. Important criteria for the use of Karnasch VHM drills Recommended cutting data for HSC-micro-drill, without interior cooling supply Material group Material Cutting speed Vc (m/min) Recommended feed rate (mm per rev.) based diameter range 0.5 0.8 1.0 1.2 1.6 2.0 2.5 3.0 1.1 – 1.2 – 1.3 St37, St42, C22, 653P St50, St 60, CK45, C35, 45Mn6 60 - 160 <0.05 <0.10 <0.12 <0.15 <0.20 <0.25 <0.28 <0.35 1.4 – 1.5 – 2.1 53MnSi4, 16MnCr5 90MnCrV8, 31NiCr14 CK60, 41CrAlMo7 50 - 120 <0.02 <0.04 <0.06 <0.14 <0.25 <0.28 <0.30 <0.35 2.1 100Cr6, 20MnCr5, 31CrMo12, 42CrMo4, 14CrNi14 50 - 100 <0.02 <0.06 <0.08 <0.12 <0.16 <0.20 <0.22 <0.25 3.1 – 3.2 X210CrW12, X165CrMoV12, 75CrMoNi6, 56NiCrMoV7 30 - 60 <0.02 <0.07 <0.12 <0.15 <0.20 <0.25 <0.28 <0.30 7.1 – 7.2 – 7.3 7.4 – 7.5 – 7.6 GG20 - GG 50 GGG40 - GGG70 GTW/GTS < 150 <0.05 <0.15 <0.20 <0.25 <0.30 <0.35 <0.40 <0.45 11 Index 10 9 OIL 8 7 6 5 4 3 2 1