Wire-cut electrical-discharge machining (EDM) is primarily used for small production lot sizes where either extreme precision is required or other cutting technologies are not readily available. Wire-cut EDM cuts keyways by eroding material away from the workpiece through a series of rapid electric current discharges between a spooling wire and the workpiece through a dielectric liquid. Computer numerical control (CNC) wire-cut EDM machines allow for a wide variety selection of keyways to be cut, inclusive of multiple keyways on the same hub. The main limitations of CNC wire-cut EDM is the time it takes to cut a keyway as well as the size of parts a given wire-cut EDM machine can accommodate. [9] Shaping or slotting [ edit ] a b Cutting Keyways - Broaching, Keyseating, Wire-Cut EDM, Shaping, & Milling , retrieved 2014-12-03. The term spline comes from the flexible spline devices used by shipbuilders and draftsmen to draw smooth shapes. Rotational ball splines integrate linear and rotary motion in one device, whereas standard ball splines provide both linear and torque transmission. Shaping or slotting is largely used for cutting keyways that do not extend through the full length of the part. Like keyseating, shaping uses a single-point cutting tool for cutting, however, shapers are not guided through the cut on a fixed post. As such, shaper cuts are generally more susceptible to deflection than keyseater cuts. [9] Milling [ edit ]

Tangent keys are used in high-torque heavy-duty applications. What would have been the side of each keyway forms heels against which the key sits, and transfers force compressively. This latter point means that for reversible motion of the shaft, another key along a tangent outwards in the opposing direction is needed. Typically this will be offset by 90° or 180° on the shaft. The key may be wedge, rectangular, or square shaped, but particularly rectangular double-taper keys are used.In interpolating problems, spline interpolation is often preferred to polynomial interpolation because it yields similar results, even when using low degree polynomials, while avoiding Runge's phenomenon for higher degrees. Serrations are employed in instrument drives, valve shafts, and other applications. Helical Splines- A Hirth joint is similar to a spline joint but with the teeth on the end of the shaft instead of on the surface. Ball splines are frequently grouped with recirculating linear bearing guides (also known as linear bushings), although they have advantages over standard linear bushings.

These might be in the form of parallel or involute teeth. The lead and helix angles of the helical spline are specified. These splines have a variety of applications.

Parallel, tapered, and Woodruff keyways can be produced on a milling machine. End mills or slotting cutters are used for parallel and tapered keyways, while a Woodruff cutter is used for Woodruff keyways. [10]