A method of cutting metallic foams that eliminates the problem of smeared surfaces is provided. The method involves infiltration of the foam with another material to serve as a support structure to the foam when being cut. The method can be executed using softer polymeric materials such as waxes, which are then frozen for machining. These materials are subsequently heated and removed from the foam. In a similar manner, epoxy material can be used, which requires no freezing. In this method, the epoxy material is burnt from the foam upon completion of machining. The method allows for machining foams using conventional machining processes, rather than non traditional methods such as electrical discharge machining.

A hole-saw comprises a tubular body connectable at one end to inter alia a power drill and formed at its other end with an annular array of cutting teeth. A collar is positioned at the end of the tubular body remote from the cutting teeth, the perimeter of the collar extending generally normal to and beyond the perimeter of the tubular body.

A hole-saw comprises a tubular body connectable at one end to inter alia a power drill and formed at its other end with an annular array of cutting teeth. A collar is positioned at the end of the tubular body remote from the cutting teeth, the perimeter of the collar extending generally normal to and beyond the perimeter of the tubular body.

A drilling guard is provided for mounting on a drill head or a drill chuck of a drilling machine, in particular a cordless drill, for protecting the drilling surface against damage during drilling. A method for producing a borehole by using a drilling machine and the drilling guard is also provided.