Demolition Series Cobalt Bi-Metal Reciprocating Saw Blades. Demolition Blades Are Made From Cobalt High Speed Steel Teeth And Have A Shatterproof Shock Absorbing Alloy Backbone. 7/8″ Width And Have Duty Blade Thickness Handles Demolition And Remodeling Projects Where Other Blades Fail. 1/2″ Universal Shank Fits All Popular Reciprocating Saws. Extra Thick, Extra Wide Blade For All Types Of Hard To Cut Demolition Work. Fast Plunge Cutting In Wood, Nail Embedded Wood, Plaster And Aluminum.