“In modular drilling, you’re only as strong as your interface, and that’s the secret behind the KenTIP FS,” says Kennametal engineer Steve George. Learn more about the features that enable the KenTIP FS modular drill to match the productivity of solid carbide drills.
Q: Why do people choose modular drills over solid carbide?
A standard modular drill is less expensive at large diameters and long lengths than a solid carbide one. Also, you don’t need to recondition a modular drill because you can just change the inserts. The tradeoff is that a modular drill typically delivers less rigidity and stability, less heat and load resistance, and often lower metal removal rates.
Q: So, when is a solid carbide drill a better choice?
When application-specific performance is needed, machinists and engineers choose solid carbide drills for their high precision and high metal removal rates. A typical solid carbide drill also usually has a high length to diameter capability. But its disadvantage is the need to regrind, which changes the diameter and length each time it’s done.
Q: How does the KenTIP FS bridge the performance gap?
We set out to create a modular drill that would maintain flexibility and cost-efficiency but would also reach the productivity levels reserved, until that point, for solid carbide drills.
To make it happen we had to rethink the design of the carbide insert and the clamping mechanism. The result is a full solid carbide front, which helps in two ways. It ensures that chip formation happens only on carbide, so the drill body does not have to battle abrasive wear. Secondly, it protects the interface and helps to extend the tool life of the drill body.
The KenTIP FS has wider and deeper flutes than other modular drills. The ultra-high polished chip flutes enable reliable chip evacuation with less friction, resulting in less holder wash-out and longer tool life.
Q: How does the tip hold on to the body, and how strong is that connection?
This is the most interesting part! With modular drilling, you’re only as strong as your interface – a point where an insert and a body are connected. We had to make that connection as strong as possible, so it could handle high forces and reach the increased feed rates. To design the best solution, we gathered a global team of engineers, including metal cutting specialists from the US, Germany, and India. Together, we created an innovative interface that reduces stress. Less stress in “the pocket seat” means the KenTIP FS can handle more forces. And that allows you to push the drill harder for higher feed rates.
The secrets of the interface.
Q: High speed and feed rates typically mean more heat. How does the KenTIP FS deliver efficient coolant?
Achieving efficient cooling and lubrication in the cutting zone is one of the main challenges in drilling. Experience shows that different approaches are required to get the best results in different workpiece materials. So, we needed the coolant flow to change as the inserts for different materials change. While most of the modular drill systems on the market have just two coolant holes, the KenTIP FS drill body has four coolant holes.
Adhesion and flank wear are a big concern in stainless steel and cast irons. Inserts with HPL and HPC point geometry have coolant channels to provide better lubrication in this area to overcome the issue. In steels though, it’s better to concentrate coolant to the rake face and take the heat from the contact zone between chip and rake face. To raise insert tool life and improve chip breakage in steels, the HPG point geometry comes without coolant channels.
Q: A strong interface, an innovative coolant system… Are we still able to change the inserts easily?
We made the process of changing the inserts as smooth as possible. Just clean the pocket with an air blast, put the insert into the pocket with your fingers, and tighten it with the wrench you receive with each KenTIP FS. You can do all that without even taking the tool’s body out of your machine. Timesaving, isn’t it?
