Page 203 - Demo

201CENTER DRILLING%u00bd%u0009Center DrillsCenter drills are profile drilling tools which were specially developed for machining centering holes. The center drill performs a combination of two operations simultaneously: drilling and countersinking. Therefore, the center drill is often referenced as a %u201ccombined countersink%u201d. Another name for the center drill, although rarely used, is a %u201cSlocombe drill%u201d.ISCAR center drills are designed according to DIN 333 for center holes according to DIN 332Centering drills may differ in the following parameters:%u2022 Construction %u2013 one or double-sided%u2022 Material - the most common center drills are carbide and HSS%u2022 Type %u2013 A, B, etc.%u2022 Dimensions %u2013 depending on the workpiece%u2019s features (overall dimensions, weight, etc.)%u2022 Hardness %u2013 usually 63-66 HRcCentering drills are selected based on the requirements for the centering hole in the design drawings.