Abstract: A cutting tool with through coolant has an elongated shank and a cutting portion. The cutting portion is configured to remove material from a workpiece by cutting. An outer peripheral surface of the shank is configured to be surrounded and tightly held by a hole-wall defined by a tool-fixing hole of a machine tool. At least one coolant-guiding recess is formed in the outer peripheral surface of the shank and extends along a lengthwise direction of the shank. Each coolant-guiding recess forms a coolant channel together with the hole-wall of the tool-fixing hole. An end of the coolant channel is connected to a coolant-supply system. The coolant channel formed by the coolant-guiding recess enables coolant from the coolant-supply system to be jetted toward the cutting portion. The cutting tool provides through coolant without drilled holes, thereby saving cost.

Abstract: Disclosed is an assembling and centering structure for a processing tool, the structure having a clamping handle (10), a processing head (20), and a fastening member (30) for connecting and fixing the clamping handle (10) and the processing head (20). An end face accommodation groove (100) of the clamping handle (10) is formed with a concave part (11) and a centering hole (12). The processing head (20) is formed with a convex part (211) and a centering post (222), the convex part (211) matches the concave part (11), and the centering post (222) matches the centering hole (12). Thus, it can be ensured that after assembly, the central axis of rotation of the clamping handle (10) is in a straight line with the central axis of rotation of the processing head (20).

Abstract: A screw tap with replaceable tool bit has a holding body, a detachable blade, and a fixing element. The holding body has a receiving area and a first engaging portion. The detachable blade is mounted in the receiving area of the holding body and has a second engaging portion, and the second sharp part of the second engaging portion engages with the first sharp part of the first engaging portion. The fixing element is securely mounted through the holding body and the detachable blade. The detachable blade can disassemble from the holding body, and thus one holding body could be installed with detachable blades of various dimensions. As the detachable blade is damaged, the damaged detachable blade is replaced with a new detachable blade to keep processing.

Abstract: A drill bit has a butt and a shaft. The shaft connects to the butt and has a central axis, a tip, multiple grooves and multiple steps. The grooves are formed in the shaft, and each groove has a force-bearing surface. The steps are formed on the tip of the shaft outward from the central axis. Each step has at least one cutting edge on the cutting step and aligning with the force-bearing surface.