Patent ID: 7165922

Claim:
A cutting tool assembly comprising: an arbor including a tapered shank portion which has a taper of 7/24 and a spindle nose size of No.30; a cutting tool having at least one cutting blade and fastened to said arbor, said cutting tool being a face milling cutter having a cutting diameter of 80–160 mm; a fastener for fastening said cutting tool to said arbor; and a relative-rotation preventing mechanism for preventing rotation of said cutting tool relative to said arbor; wherein said cutting tool assembly has a weight of not larger than 3 kg; wherein said arbor and said cutting tool have respective contact surfaces which are held in contact with each other; wherein said relative-rotation preventing mechanism is configured by three receiving holes on one of said contact surfaces, and three pins which are formed on the other of said contact surfaces, where an inner shape and size of said receiving hole is substantially identical to an outer shape and size of the pin so that each pin is fitted in the corresponding receiving hole; wherein said arbor comprises an annular flange portion which provides the contact surface and has a pair of driving slots formed in an outer circumferential surface of said annular flange portion; and wherein said three pins are spaced equally apart from one another in a circumferential direction of the arbor, and said three pins are positioned relative to said pair of driving slots such that one of said pins is farthest from said driving slots and the two remaining pins do not overlap with said pair of driving slots as seen in an axial direction of said cutting tool assembly.