Cool Blocks blade guides are made from a high tech, non-metallic composite material, Graphite Impregnated Phenolic Laminate” with three synthetic dry lubricants that lubricate the blade but don’t make it oily. Metal to metal contact made by ordinary guide blocks creates heat, friction and premature blade wear and breakage. With Cool Blocks blades run cooler and last longer. Cool Blocks improve the performance of any blade and are most effective with 1/16in. and 1/8in. wide blades for tight radius cuts.