PLANE (Fr. plane, from ML. piano, plane, from Lat. planare, to plane, level, from piano; level, flat, plane, plain). \ tool used for render ing the surface cif wood sn ooth and level. it consists of an oblong block of wood or metal with an opening t 111'0101 the centre; this open ing is square on the upper side. and is always large enough to admit the cutting instrument: it diminishes down to a mere slit on the under side. jilt-4 wide enough to allow the cutting edge of the plane•iron and the shaving of wood which it cuts uff to pas, through. The essential part of the tool is the plane-iron. a piece of steel with a chisel-shaped edge. and a slot in its centre for a large-headed screw• to work and to attach it a strengthening plate. In the older wooden planes it was held in place by the hard-wood wedge. fly driving in the wedge• the irons ate held very firmly in their place, and they are so adjusted that only the line sharp chisel edge of the cutting-tool projects through the slit in the bottom of the hodv of the plane, so that when the tool is pushed forward by the fore'. of the hand
the cutting edge pares off all irregularities, until the wood is as smooth as the tinder surface of tire plane. In the iron planes now• used the iron is held in the block and adjusted by a screw. There are many modifications in this tool, which can have its cutting edge and under surface made to almost any contour. so that moldings of all kinds may be made. The two commonest are the jack-phine, for rough work, and the smoothing plane, for finishing otl' plane surfaces. plan ing machines, see METAL WORKING MACHINERY and \l'iton-WoRKING AlACHINERY.