b axis: The angle that specifies the rotation of a machine tool about the y axis.
B-B fraction: A mixture of butanes and butenes distilled from a solution of light liquid hydrocarbons.
B-H meter: A device used to measure the intrinsic hysteresis loop of a sample of magnetic material.
back boxing: NULL
back check: In a hydraulic door closer, a mechanism that slows the speed with which a door may be opened.
back edging: Cutting through a glazed ceramic pipe by first chipping through the glaze around the outside and then chipping the pipe itself.
back end: NULL
back fillet: The return of the margin of a groin, doorjamb, or window jamb when it projects beyond a wall.
back gearing: The technique of using gears on machine tools to obtain an increase in the number of speed changes that can be gotten with cone belt drives.
back gutter: A gutter installed on the uphill side of a chimney on a sloping roof to divert water around the chimney.
back hearth: That part of the hearth (or floor) which is contained within the fireplace itself. Also known as inner hearth.
back jamb: NULL
back lintel: A lintel which supports the backing of a masonry wall, as opposed to the lintel supporting the facing material.
back mixing: The tendency of reacted chemicals to intermingle with unreacted feed in reactors, such as stirred tanks, packed towers, and baffled tanks.
back nailing: Nailing the plies of a built-up roof to the substrate to prevent slippage.