| Bell Mouth | (english) The flaring or tapering of a machined hole, usually made at the entrance end because of misalignment or spring of the cutting tool. |
| Bench Grinder | (english) A small grinding machine for shaping and sharpening the cutting edges of tools. |
| Bench-Blower | (english) A small core-blowing machine, utilizing a removable sand magazine and blow heat. |
| Bifluoride Feeder | (english) A machine in the Tin Mill that automatically puts bifluoride into the plater bath. |
| Bit, Tool (cutter) | (english) A hardened steel bar or plate that is shaped accordidng to the operation to be performed and the material to be machined. |
| Boss | (english) A projection or an enlarged section of a casting through which a hole may be machine. |
| Brass | (english) An alloy that is 70% copper,30% zinc. One of the most widely used of the copper-zinc alloys; malleable and ductile; excellent cold-working but poor hot-working and machining properties; excellent for soft-soldering; good for silver alloy brazing or oxyacetylene welding, but fair for resistance or carbon-arc welding. Used for drawn cartridges, tubes, eyelets machine items and snap fasteners. |
| Break Test (for tempered steel) | (english) A method of testing hardened and tempered high carbon spring steel strip wherein the specimen is held and bent across the grain in a vice-like calibrated testing machine. Pressure is applied until the metal fractures at which point a reading is taken and compared with a standard chart of brake limitations for various thickness ranges. |
| Broaching | (english) Smoothing machined holes or outside surfaces of castings by drawing pushing on or more broaches (special cutting tools) through the roughed out hole. |
| Pumping (of Pavements) | (Concrete Engineering) The ejection of a mixture of water and solid materials such as clay or silt along cracks, transverse or longitudinal joints, and along pavement edges caused by downward slab movement due to the passage of heavy loads, machinery or equipment over the pavement after free water has accumulated in or on the subbase, subgrade or basecourse. |