Did you want to put a railing around your concrete porch but got tired of trying to drill anchor holes with your regular drill? Well now that you bought the Bosch 18 Volt Litheon Hammer Drill, use these Hammer Drill bits and finish the job. They can drill through concrete, stone, or masonry. The magic is in the carbide tip. It can withstand the hammering action of a hammer drill and that hammering action helps to pulverized the concrete and make the hole. The carbide tip has been brazed at a low voltage and at very high temperatures to keep the cutting edge from breaking, even with the heat of deep drilling. Special deep flutes help remove the concrete dust for fast drilling. Bits will fit any competitive three jaw chuck hammer drill. Made in China.