GRAFF Master countersink bit 8,3 mm for M4 thread is intended for processing non-ferrous metals, alloy and non-alloy steel. It is used for rough processing and finishing of conic or cylindrical holes. This type of countersinking allows to make holes with bigger diameters, while improving quality of processed surface. A countersink bit has U-type cutting edge with cubic boron nitride sharpening. Such a countersink bit is made according to DIN 335 from high-speed steel P6M5. A point angle is 90 degrees.
When machining with a countersink bit which has a diameter of 8,3 mm, cutting speed should not exceed 500 rpm.
Parameters of a countersink bit with a diameter of 8,3 mm: diameter – 8,3 mm; thread size – M4; total length – 50 mm; shank diameter – 6 mm.