Spyder Tungsten Carbide Tipped (TCT) Reciprocating Saw Blades 18"Tungsten carbide teeth combined with the power of a reciprocating saw quickly cut through brick and mortar, stone, concrete (cinder) block, timber and much more. Recommended for use on concrete products, brick or timber materials make sure to check the Mohs hardness of the material being cut. 9 In blade quickly cuts through concrete block, brick, masonry and timber Make square and flush cuts access hard to reach areas Fits all reciprocating saws