HSS drills are designed for drilling hard and tough materials such as ceramics. The drills are made of carbide alloy and allow you to make neat holes without excessive dust. The drills have a large margin of wear resistance as the tips are coated with titanium material. The set comes with 6 drills with a diameter of 4, 5, 6, 8, 10 and 12 mm. Buyers in reviews praise the quality of the product: the holes are obtained without chipping.