The CBTz chipbreaking technology used in Emuge’s Rekord DZBF series taps is designed to eliminate the formation of long, continuous chips that commonly occurs when tapping carbon steels, alloy steels and austenitic stainless steels. The taps are suited for machining applications in energy and related industries.
The taps feature a cutting-face geometry and spiral-flute form designed to improve chip flow, curl and length. This chipbreaking technology produces short, broken, controllable chip formations designed to eliminate flute clogging and potential failure of the machine tap due to chipped cutting teeth or breakage. Benefits are said to include increased threading-process reliability, tool life, surface-finish quality and operator safety. It also reduces machine downtime required for chip cleaning.
The taps are made of premium cobalt high speed steel and ground with eccentrically relieved threads that feature full-pitch diameter relief. This is designed to increase machining efficiency compared to conventional taps. A TiN surface treatment reduces friction between the tap and workpiece, which improves thread finishes and increases tool life in carbon and alloy steels, cast and forged steels, tool and die steels, and 300 stainless steel as hard as 35 HRc.
To add an additional wear allowance for improved tool life, the taps also are ground with an increased pitch diameter, designated 2BX, which optimizes the gage tolerance for a 2B class of fit. The taps are feature long shanks, DIN length for extra reach, and improved chip evacuation, cooling and lubrication.
The taps are available in sizes ranging from 0.5" to 2" and are designed to be used in both horizontal and vertical machining applications. According to the company, this saves tooling change-over time and eliminates the need to stock two lines of taps in the tool crib. A modified bottom chamfer is suited for blind holes.