Crown tap N470V-4

monoblocfor blind holesthrough-hole

The DC crown tap with ”V” surface treatment to prevent cold welding is a tool of high performance, which offers a very high quality surface finish of the tapped threads. Thanks to the front recess providing space for the chip collection, the DC crown tap is suitable for both, through and blind hole tapping. The crown tap can be used for materials with a tensile strength up to 850 N/mm2 and an elongation of maximum 30 %. For an optimal blind hole threading, the core hole depth must be adapted accordingly and the following application instructions must be followed: - tap until tapping head clutch slips - retract tap and clear chips - tap to the full depth. The efficient operation of DC crown taps, as well as the quality of the cut threads, depend on observation of the following rules: - do not exceed the maximum permissible centering error of 0.1 mm - the tap must run concentrically, use a suitable tapping head - tap at the correct cutting speed - select a coolant to suit the material being tapped - use a tapping head with axial compensation and safety clutch - set the safety clutch so that it will slip at just above the tapping torque. When tapping the first hole, slacken the clutch until it slips, then gradually tighten it until the tap is driven