Abstract: A clutch includes balls, an axle, a socket and a cylinder. The axle includes a circular section formed with alternate cavities and ridges. The socket includes a circular bore for receiving the circular section of the axle and apertures for receiving the balls. The cylinder includes an annular recess made in an internal face. The socket is movable in the cylinder between two positions. When the socket is the first position, the internal face of the cylinder abuts the external portions of balls to engage the internal portions of the balls with the ridges to cause the axle to rotate the socket via the balls. When the socket is in the second position, the annular recess receives the external portions of the balls to allow disengagement of the internal portions of balls from the ridges to allow the axle to rotate relative to the socket.

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: 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: Disclosed is a method for making a bit of a tool. The method includes the steps of providing a blank, forging, cutting and pressing. The size of the blank is determined according to the size of the bit. By the forging, the blank is made with a connective section and a neck. The connective section is formed with a polygonal profile, a first chamfer at an end thereof and a second chamfer at another end thereof. The neck extends from the polygonal connective section and includes ribs separated from one another by grooves. By the cutting, the neck is made with a tapered section. By the pressing, the tapered section of the neck is turned into a driving section of the bit to reduce the length of the tapered section of the neck but increase the width of the tapered section of the blank.

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.

Abstract: A screwdriver includes a shank and a head formed at an end of the shank. The shank is made with a diameter. The head is formed with blades. Each of the blades includes an edge. The distance between the edges of any two opposite ones of the blades is larger than the diameter of the shank.

Abstract: A floatable hand tool includes a shank having an inner wall formed with an axially extending through hole, and a tool tip mounted on an end of the shank and having an end portion provided with a protruding connecting rod inserted into the through hole of the shank so that the through hole of the shank forms a closed chamber. Thus, the floatable hand tool floats on the water level by the floating force produced by the closed chamber the through hole of the shank. In addition, the floatable hand tool floats on the water level, thereby preventing the floatable hand tool from being missed when falling into the water, and thereby facilitating a user operating the floatable hand tool in the water.