Level surface & floor preparation HTC diamond tools Tool holders on an HTC 1500 ixT grinding head HTC's metal-bond diamond tools are constantly being developed to meet our customers’ requirements for efficient grinding tools. HTC has developed a very broad range of metal-bond diamond tools to achieve maximum capacity at minimum cost and to suit most types of floor. Floors can be divided into different categories, such as soft floors, medium-hard floors and hard floors. Soft floors Floors of loose or porous material. A high rate of removal is achieved with these floors, but with higher tool wear. Medium-hard floors Normal building concrete. This includes marble and terrazzo floors. Hard floors Usually refers to steel trowelled floors or certain types of cement. This includes granite. The floors usually require “soft” segments.