| Blowhole 2 | (english) A cavity which was produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets. |
| Blue Annealing | (english) Heating hot rolled ferrous sheet in an open furnace to a temperature within the transformation range and then cooling in air, in order to soften the metal. The formation of a bluish oxide on the surface is incidental. |
| Blue Brittleness 2 | (english) Reduced ductility occurring as a result of strain aging, when certain ferrous alloys are worked between 300 and 700 (degrees) F. This phenomenon may be observed at the working temperature or subsequently at lower temperatures. |
| Boil | (english) Agitation of a bath of metal caused by the liberation of a gas beneath its surface. May be deliberately induced by the addition of oxidizing material to a bath containing excess carbon. In the later case it is called a carbon boil and CO or CO2 are liberated. |
| Bolster (die block) | (english) A “tool” or reinforcing part which supports the backer-which, in turn, supports an extruding die against the pressure of extrusion. |
| Bonderized Coating | (english) A thin film of phosphate pretreatment applied to a steel surface (bare or zinc coated) to enhance paintability. |
| Bonderizing | (english) The coating of steel with a film composed largely of zinc phosphate in order to develop a better bonding surface for paint or lacquer. |
| Boron Steels | (english) The addition of boron in the range 0.0005-0.005% to certain steels increases the hardenability. A range of boron steels is now listed in the current BS 970 and are widely used for the production of cold headed fastenings. |
| Bow | (english) The lateral deviation from straightness |
| Box Annealing | (english) Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called close annealing or pot annealing. |