Abstract: A reamer includes a shank, a washer, a ring and a blade. The shank is a polygonal rod and includes an annular groove made in a periphery and a bore made in an end. The washer includes a slot. The ring includes a circular opening. The blade includes an insert inserted in the bore through the slot and the circular opening. The circular opening is made of a diameter larger than a width of the blade to allow the blade to rotate relative to the ring.

Abstract: An apparatus is disclosed for making aligned inclined holes in upper and lower work piece. The apparatus includes a set of drill bits and an alignment element. Each of the drill bits can be driven into the upper and lower work pieces to make the inclined holes. The alignment element includes a horizontal plate, a vertical plate extended from the horizontal plate and a tube extended from a corner formed between the horizontal and vertical plates. The horizontal plate is used for contact with the upper work piece. The vertical plate is used for contact with the lower work piece. The tube includes a tunnel for receiving a selected one of the drill bits, a space for receiving debris produced because of the drilling and an aperture through which the selected drill bit is inserted into the space from the tunnel.