732 Каталог ISCAR 2017 Вращающийся режущий инструмент и инструментальная оснастка Стр.728

Каталог ISCAR 2017 Ротационный инструмент Стр. 728 0732 ENG Lab2u

TAPS USER GUIDE Tap Tolerances Nut thread Tolerance Nut thread positioning of classes for positioning of H tolerance taps G tolerance Au = Basic Deviation of Pitch For Optimum Tapping Conditions, Reduced Machining Times and Increased Tap Life Selection of the Most Suitable Tap As a general rule, materials with deformation capability of at least 10% can be cold-formed. To decide on the most suitable tap, please refer to the tap recommendation table on page 706. Pre-Tapping Holes Check that the holes are within the prescribed size range depending on the application (see table on page 720) The holes should be clean and swarf-free. Lubrication Frequently the lubricant content of the coolant used for general machining is too low for tapping. If it is not possible to increase the lubricant content, following are some possible solutions: A separate lubricating unit can be connected to the machine control, to deliver the required quantity of concentrated emulsion into the core hole or onto the tap. Tapping in separate operations allows the use of the ideal tapping lubricant. Tapping Speeds The tapping speed has a great influence on chip flow and the life of the tap. It is worthwhile to establish the ideal speed by tapping trials. For recommended initial values, see table on page 706. In addition, the following should be taken into consideration: characteristics of the material, machine and clamping method. Effects of Unsuitable Tapping Speed forced tapping tap lead chipping caused by overloaded cutting tooth torn threads unsatisfactory tap life rejected threads 728 ISCAR