Abstract: The invention relates to a rotary tool having at least one replaceable cutting blade, the or each received in a channel and clamped firmly therein. The tool body has a passage in each channel which receives a safety member in the form of a pin projecting into a recess in the blade. In normal use the pin remains out of contact with the walls of the blade recess, engaging with the recess only if the clamping means fail, so as to restrain the blade from falling out of the channel.

Abstract: A flute piece consisting of a piece of tungsten carbide twisted or formed such that the flute piece has at least two helical cutting edges and an axis through which the tungsten carbide material extends. The flute piece is intended for an engineers' tool for working ferrous or non-ferrous metal, plastics or wood, such as a twist drill or a milling or boring cutter for a machine tool. A shank member has an extension web on one end thereof which is provided with a helical slot for reception of the flute piece.

Abstract: A method for producing a cutting face from a hard cutting material for engineer's tools comprising, essentially, presenting the metal stock to a feed slot within a forming core, heating the same to its deformation temperature and then forcing now deformed stock through said forming core into the desired shape. A helical cutting face produced by such method having a length greater than one-third its total lead; a helix angle in the range of 10.degree.-45.degree.; being of a length of one and one-half inches upward depending upon the particular tool requirement; and being of any desired cross-section.