| Blast Furnace Gas | (english) By-product gas created by the iron making process which is used as fuel for the boilers. |
| Blasting (Blast Cleaning) | (english) A process for cleaning or finishing metal objects by use of an air blast or centrifugal wheel that throws abrasive particles against the surface of the work pieces. Small, irregular particles of steel or iron are used as the abrasive in grit blasting, and steel or iron balls in shot blasting. |
| Blister | (english) 1) Coating defect consisting of the formation of bubbles in a coating, which appear as hemispherical elevations. The blisters are hollow, and are usually caused by entrapped air or solvent. 2) A raised spot on the surface on the surface of metal due to expansion of gas which causes a subsurface metal separation such as inclusions and small laminations. |
| Blister 2 | (english) A defect in metal, on or near the surface, resulting from the expansion of gas in a subsurface zone. Very small blisters are called pinheads or pepper blisters. |
| Block, Jo | (english) Shop name for a Johnnson gage block, a very accurate measuring device. |
| Blowhole | (english) A defect in a casting caused by trapped steam or gas. |
| 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. |
| 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. |
| Bottle Top Mold | (english) Ingot mold, with the top constricted; used in the manufacture of capped steel, the metal in the constriction being covered with a cap fitting into the bottle-neck, which stops rimming action by trapping escaping gases. |