A router is a woodworking tool used to rout out (hollow out) an area in the face of a piece of wood. It was a tool particularly used by pattern makers and staircase makers and consisted of a broad-based wooden hand plane with a narrow blade projecting well beyond its base plate gaining it the nickname Old Woman's Tooth. Since about 1960, it has been replaced by the modern spindle router, which was designed for the same work, although the first electric hand routers appeared in the years just after World War I. Further refinement produced the plunge router, invented by Elu (now part of deWalt) in Germany in the late 1940s. This is even better adapted for many types of work. Today, traditional hand-powered routers are often called router planes. Modern routers are often used in place of traditional moulding planes or spindle moulder machines for edge decoration (moulding) of timber. Related to the router, is a smaller lighter version designed specifically for trimming laminates. It can be used for smaller general routing work. For example with an appropriate jig it can be used recessing door hinges and recessing lock faceplates etc. A wood CNC Router is similar to a metal CNC mill with the following differences:The wood router typically spins faster — up to 24,000 RPM It typically uses smaller tools — typical shank size 20 mm or at most 25 mm. It typically uses smaller toolholders MK2 (Morse taper #2 - on older machines),ISO-30, HSK-63 or the tools just get held in a collet tool holder affixed directly to the spindle nose. ISO-30 and HSK-63 are rapid-change toolholding systems. HSK-63 has begun to supplant the ISO-30 as the rapid change standard in recent years Some wood routers have multiple separate heads that can come down simultaneously or not. This design is generally not as easy as a toolchanger with ISO-30 or HSK-63, though it is easier to maintain. A wood router table is controlled in the same way as a metal mill, but there is a lot of CAM software specifically for wood routers. Wood with different grain must be approached with unique strategies, and wood CAM software is less likely to need to have hog-out strategies than the metal ones. Wood routers are frequently used to machine other soft materials such as plastics at high speed.