Slotting machine is a linear motion machine tool that uses the vertical reciprocating motion of the slotting tool to slot the keyway and the hole. The slotting machine, like the planer, also uses a single-edged tool (slotting tool) to cut the workpiece, but the planer is a horizontal layout, and the slotting machine is a vertical layout. Slotting machines have low productivity and accuracy. They are mostly used for processing inner keyways or spline holes in single or small batch production. They can also process flat, square or polygonal holes. They are often replaced by milling machines or broaching machines in mass production. But when processing the keyway of the inner hole with no through hole or obstructive shoulder, only the slotting machine is used. Slotting machines mainly include ordinary slotting machines, key slotting machines, gantry slotting machines and mobile slotting machines. The ram of the ordinary slotting machine carries the tool holder to move up and down along the guide rail of the column. The worktable with the workpiece can use the up and down seat for longitudinal, lateral and rotary feed movement. The worktable of the key slot slotting machine is integrated with the bed. The tool bar extending upward from the bed through the workpiece hole carries the inserting knife while doing up and down reciprocating motions while doing intermittent feed motion. The workpiece installation is not like ordinary slotting machines. Because it is limited by the column, it is mostly used to process the keyway in the hole of large parts (such as propellers, etc.).

The slotting machine is actually a vertical planer, which belongs to the same type as the bull's head planer in terms of structure. The linear reciprocating movement of the plunger in the vertical direction with the ram is the main movement, and the intermittent movement of the workpiece along the longitudinal, transverse and circumferential directions is the feed movement. The production efficiency of the slotting machine is low, the surface roughness Ra of the processing surface is 6.3-1.6 microns, and the perpendicularity of the processing surface is 0.025/300 mm. The main parameter of slotting machine is the maximum slotting length.

The slotting machine is used for slotting planes, forming surfaces and keyways, etc., and can insert work objects such as molds with an inclination within 10°. It is suitable for single or small batch production enterprises. The worktable of the slotting machine has three different directions of feed (longitudinal, horizontal and rotary), so after the work piece is clamped once, several surfaces are processed on this machine.