A cleaning method allows reliable cleaning of thread roots of a female screw. A cleaning method for a female screw includes producing a jet of a cleaning liquid from a nozzle in a direction tilted from an axis of the female screw without inserting the nozzle in the female screw, and directing the jet to impinge on a thread of the female screw while rotating the jet about the axis.

A cutting tool includes a body including a connecting end, a cutting end which includes a space for receiving the work piece, at least one projection with a ridge defining at least one cutting edge for cutting the work piece, and at least one slot for allowing pieces trimmed from the workpiece to exit from the body. The space has a top and a bottom and tapers outwardly from the top to the bottom. The at least one cutting edge has a first end adjacent to the top of the space and a second end adjacent to the bottom of the space and extends from the first end to the second end obliquely. The body is rotatable about a first axis, and the first axis extends longitudinally between the first and second ends of the body.

A threaded rod cutter includes a shear assembly and a drive assembly; the shear assembly includes a shear base, a stationary blade, a shear lever, a moving blade, a reset spring, a cam, and a roller; the drive assembly includes an electric motor for driving the cam and a speed reducer; a lower concave surface, an involute surface, and a circular fillet surface connecting the lower concave surface and the involute surface are arranged along a peripheral direction of the cam; when the roller engages the lower concave surface, the threaded rod cutter is in a ready-to-shear state; when the roller rotates past the lower concave surface to engage the involute surface, the involute surface drives the shear lever to swing so that the shear lever drives the moving blade to be fitted with the stationary blade to shear a threaded rod.