808 Каталог GUHRING 2016 Режущий инструмент для обработки наружной и внутренней резьбы Стр.796

Каталог GUHRING 2016 Режущий инструмент для резьбы Стр. 796 0808 Lab2u

Technical section GENERAL INFORMATION THREAD FORMING “Profile“- Guhring’s new fluteless tap generation Characteristics and advantages Conventional fluteless taps, produced by a grinding process only, show traces of microscopic, very fine grinding marks on the surface of the tool. This also applies to the threaded portion of the tool required to perform the thread forming operation. This surface topography (structure) has a negative effect on the friction between the tool and the material to be re-formed as well as on the herewith associated heat development, on the necessary torque and last but not least on the wear of the pressure points of the fluteless tap. In addition, the “grinding marks” encourage the build-up of the material to be re-formed in the thread flanks of the fluteless tap. This is also called cold welding. For the user, a longer tool life and increased cutting speeds are the benefits of this special process. The tool life can be increased considerably depending on the material to be machined and the application condi-tions. A 100% increase in tool life is not unusual. The improved surface topography is not only of benefit to tools with bright finish. Particularly coated tools also benefit from the new process. Outer contour and forming lead greatly determine the performance of the fluteless tap. Numerous tests have shown that fluteless taps with optimal pressure point geometry and quantity achieve increased tool life and dimensional accuracy. Further improvements in quality are achieved when the fluteless tap is produced completely in one setting and with one grinding wheel - set-up with a special roll. Pitch errors between the thread crests and former lead transition area do not occur as with the conventional grinding process. Thanks to a special process to improve the surface topography (structure), Guhring’s new Profile fluteless taps no longer possess these “grinding marks”. This has been confirmed in research and tool life studies in varying materials under production conditions. Surface of a conventional fluteless tap Optimised surface of a Guhring Profile fluteless tap Cross section of fluteless tap A X detail x D1 = flank diameter D = nominal diameter D D1 Types of tapping size hole with fluteless taps without oil grooves for thread depth < 1 x D for thread depth > 1 x D with fluteless taps with oil grooves for all thread depths 796 GUHRING