Drilling difficult-to-machine materials with ease

The WTX-Ti from CERATIZIT makes it possible

Materials such as titanium, Inconel, VA, Hastelloy or Hardox pose significant challenges for machining technicians, machines and tools. As these difficult-to-machine materials become more common, overcoming the challenges they pose will help companies remain competitive. To assist these customers, CERATIZIT Group is investing heavily in research and development in order to transform difficult-to-machine materials into easy-to-machine materials.

The outstanding tensile strength of difficult-to-machine materials places significant demands on the tool, this is particularly the case when machining titanium, which features low thermal conductivity and high tensile strength. This sees the tools used placed under extremely high thermal and mechanical stress, making them prone to an enormously high level of wear. In addition, the cutting edges are subject to high loads, as machining results in high cutting forces – especially during drilling. Therefore, tools with coatings that boast a high degree of elevated-temperature hardness and thermal resistance lend themselves to this type of machining. The WTX-Ti high-performance drill from CERATIZIT is an excellent example: developed in response to changes in the materials market WTX-Ti impresses with its performance on difficult-to-machine materials, such as high-strength and acid-resistant steels, titanium or heat-resistant super alloys.

When designing the WTX-Ti, the development team at CERATIZIT started by responding to the needs of its customers and designed the tool to fulfil these requirements. “It was important to us to develop a high-performance drill that could be used with more than just titanium and Inconel,” explains Felix Meggle, Product Manager for Drills at CERATIZIT. He adds: “During development, we focused on ensuring that the WTX-Ti also delivers top-quality results when machining austenitic and martensitic stainless steels and Hastelloy.” Whenever CERATIZIT develops a new product, the customer and their needs are always at the heart of the process; so, while the versatility of the drill was a priority, process security and increasing productivity were also top key factors during the development of the WTX-Ti.

This was no easy task, as Felix Meggle explains: “When machining heat-resistant super alloys, the temperature at the cutting edge is very high and the materials are also very abrasive. The tool must therefore cut very smoothly and be incredibly stable in order to ensure a long service life,” he says. According to the drilling expert, VA-type drills had frequently been used in the past, for example to machine Inconel, as they are very sharp. However, this is not an ideal solution, as in practice the heat and high abrasiveness quickly lead to edge breakages on the tool. In order to reduce this wear, some innovations have been made with the WTX-Ti. A microgeometry with protective edge rounding has been used to create a very sharp yet very stable cutting edge able to withstand high loads. The polished flutes of the WTX-Ti ensure safe chip removal and less chip friction in the chip chamber, therefore reducing the temperature. Out of all these measures the most important one was the coating. “Thanks to the latest generation of DRAGONSKIN coating, the WTX-Ti is particularly wear-resistant and is ideally suited to the process due to its high thermal resistance and its extremely smooth surface,” says Felix Meggle. With its exceptionally smooth cutting and stable cutting edges, the WTX-Ti can deliver astounding results and is a significant cut above the competition.

These claims are backed-up by a variety of tests that have been carried out using the tool since its debut. “For example, in an internal test with austenitic steel, we reached a tool life of more than 72 metres. That’s huge,” emphasises Meggle. Customers are also experiencing huge success with the drill. When machining a component made from Inconel 718, a 4.4 mm diameter WTX-Ti drill created over 3000 holes at a cutting speed of 40 m/min and a feed of 0.04 mm/rev. Overall, a tool life of 36 metres was achieved, with productivity improved ten-fold compared to the competition due to the increased cutting data. Three times longer tool service lives were also achieved.

For companies operating in the aerospace, aviation, energy sectors where these materials are particularly prevalent and process security is vital, these figures will be especially attractive. “Thanks to the WTX-Ti, we can now offer the combination of high process security alongside increased productivity. What more could you want?” enthuses Felix Meggle. Aware that the market is constantly changing, the development team at CERATIZIT is always looking for the latest innovations. While WTX-Ti is a top-class drilling tool for difficult-to-machine materials they continue to work on further optimisations calling on the Group’s expertise in developing solid carbide tools, specialised carbide for these applications and tool coating technology. This expertise can then be passed directly to customers in the form of high-quality tools.

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