Reverse-keys. An arrangement of keys or wedges, that releases two pieces that have been keyed together.
Rib. A projecting strip usually employed to strengthen a piece, as the arm of a wheel.
Right-hand thread. A screw thread in which, with the end of the bolt towards you, the top of the nut must revolve from left to right like the hands of a watch in order to cause it to screw upon the bolt.
Rip-saw. A saw whose teeth are shaped to cut lengthways of the grain of the wood.
Rod-feed. A feed motion that is operated by a rod.
Roll-feed. A feed motion in which the work is fed to the cutting tool by revolving rolls.
Rope-socket. A socket in which the ends of a wire rope are secured.
Rose-bit. A reamer that cuts at the end only.
Rotary planer. An iron planing machine in which a number of cutters are set in a revolving face plate that is fed to the cut by a head on a slide.
Round-nosed chisel. A machinist’s chisel whose cutting edge is shaped so as to cut a groove circular in cross-section.