Balanced pulley. A pulley whose weight is so equally distributed that it will run steadily and smoothly at the speed for which it is balanced.
Balanced valve. A valve so constructed as to move with equal force in either direction.
Ball and socket joint. A universal joint consisting of a ball on the end of a shaft and in a casing that envelops it and yet permits it to be moved in its casing.
Ball-cutter. A tool for finishing metal balls.
Ball-pene. A spherical pene of a hammer.
Band-saw. A continuous ribbon of steel having saw teeth on one of its edges.
Band-saw machine. A machine for operating a band-saw.
Bastard file. A file whose teeth are one degree or grade coarser than a second cut file and one degree finer than a coarse cut file.
Belt. A leather band employed to drive pulleys, for transmitting motion.
Belt-clamp. A clamp for pulling the ends of a belt together, to lace it, while the belt is upon the pulleys.