Engineering Glossary: B
70 definitions in plain language.
70 terms beginning with B. Use the filter to narrow the list, or the letters to jump to another part of the glossary.
70 terms
- Backdrive #
- Driving a mechanism backward by pushing on its output, possible when it is not self-locking. Automation, controls and robotics
- Backlash #
- The small gap between meshing gear teeth that lets the gears turn slightly without moving each other. Mechanical design and mechanics
- Backlash (general) #
- Lost motion in a mechanism when its direction of movement is reversed. Math, units, quality and workshop
- Backup #
- A copy of data kept separately so that it can be restored after loss. Programming, data and computing
- Balanced load #
- A three-phase load that takes the same current in each phase. Electrical power and machines
- Balancing #
- Adjusting the mass distribution of a rotor so that it spins without vibration. Mechanical design and mechanics
- Ball bearing #
- A bearing with balls rolling between an inner and an outer ring; the most common type. Mechanical design and mechanics Read more: Deep-Groove Ball Bearing Dimensions
- Ball screw #
- A lead screw that uses recirculating balls between the screw and nut for low friction and high efficiency. Mechanical design and mechanics
- Band-pass filter #
- A filter that passes a range of frequencies. Electronics
- Bandwidth #
- The range of frequencies that a circuit or signal occupies or passes. Electronics
- Bandwidth (data) #
- The maximum rate at which data can be transferred over a link. Programming, data and computing
- Bar #
- A unit of pressure equal to 100 kPa, close to atmospheric pressure. Fluids, heat and thermodynamics
- Base unit #
- One of the seven units from which all other SI units are derived. Math, units, quality and workshop
- Basic size #
- The nominal size from which the limits of a dimension are set. Materials, manufacturing and measurement
- Bathtub curve #
- A graph of failure rate over a product's life: high at first, low and steady in mid-life, then rising with wear-out. Math, units, quality and workshop
- Battery #
- A device that stores energy chemically and delivers it as direct current. Electrical power and machines Read more: Battery Runtime and Pack Calculator
- Baud rate #
- The number of signal changes per second on a serial line; for simple serial links it equals bits per second. Programming, data and computing
- Bearing #
- A machine element that supports a moving part and reduces friction. Mechanical design and mechanics Read more: Bearings and Bearing Selection
- Bearing stress #
- The compressive stress where a pin, bolt or key presses on the wall of a hole or slot. Mechanical design and mechanics
- Bed adhesion #
- How well the first layer of a print sticks to the build plate. Materials, manufacturing and measurement
- Belleville washer #
- A conical disc spring that gives a high load in a small space. Mechanical design and mechanics
- Bench power supply #
- An adjustable power supply with voltage and current limits for testing circuits. Electronics
- Bend allowance #
- The length of the neutral axis in a bend; needed to calculate the flat pattern of a bent part. Materials, manufacturing and measurement Read more: Sheet-Metal Bend Allowance Calculator
- Bending moment #
- The internal moment in a beam that makes it bend, equal to the sum of the moments of the loads on one side of a cut. Mechanical design and mechanics Read more: Beam Bending and Deflection
- Bend radius #
- The inside radius of a bend in sheet metal or tube. Materials, manufacturing and measurement
- Bernoulli equation #
- For steady flow without friction, the sum of pressure, kinetic and potential energy per unit volume is constant along a streamline. Fluids, heat and thermodynamics
- Bevel gear #
- A conical gear used to transmit motion between shafts that meet at an angle, usually 90 degrees. Mechanical design and mechanics
- Bill of materials #
- A list of all the parts needed to build an assembly, with quantities and part numbers. Electronics
- Bill of materials (BOM) #
- A structured list of all the parts, materials and quantities needed to make a product. Math, units, quality and workshop
- Binary #
- A number system with base 2, using only the digits 0 and 1. Programming, data and computing
- Biot number #
- A dimensionless number that compares the resistance to heat flow inside a body with that at its surface. Fluids, heat and thermodynamics
- Bipolar junction transistor #
- A transistor controlled by a small base current, written BJT. Electronics
- Bit #
- The smallest unit of data in a computer, a 0 or a 1. Programming, data and computing Read more: Bitwise & Register Field Calculator
- Bit mask #
- A pattern of bits used to select, set or clear particular bits of a value. Programming, data and computing
- Bitwise operation #
- An operation that works on the individual bits of a number, such as AND, OR, XOR and shift. Programming, data and computing
- Black body #
- An ideal surface that absorbs all radiation falling on it and emits the maximum possible at its temperature. Fluids, heat and thermodynamics
- Bluetooth Low Energy #
- A low-power wireless standard for short-range communication between devices. Programming, data and computing
- Bode plot #
- A graph of gain and phase against frequency on logarithmic axes. Electronics
- Boiler #
- A closed vessel in which water is heated to make steam or hot water. Fluids, heat and thermodynamics
- Bolt #
- A threaded fastener used with a nut to clamp parts together, loaded in tension. Mechanical design and mechanics Read more: Bolted and Welded Joints
- Bolt preload #
- The tension put into a bolt by tightening, which clamps the joint together. Mechanical design and mechanics Read more: Estimated Bolt Tightening Torque (Metric)
- Bonding #
- Connecting metal parts together so they stay at the same potential. Electrical power and machines
- Bonus tolerance #
- Extra position tolerance allowed when a feature departs from its maximum material size. Materials, manufacturing and measurement
- Boost converter #
- A switching regulator that steps voltage up. Electronics
- Bootloader #
- A small program that starts when a microcontroller powers up and loads the main program. Programming, data and computing
- Boring #
- Enlarging an existing hole accurately with a single-point tool. Materials, manufacturing and measurement
- Boundary layer #
- The thin layer of fluid next to a surface where the velocity changes from zero to the free-stream value. Fluids, heat and thermodynamics
- Brake #
- A device that slows or stops motion by absorbing energy, usually as heat. Mechanical design and mechanics
- Brake (motor) #
- A holding device on a motor that locks the shaft when power is off. Automation, controls and robotics
- Braking resistor #
- A resistor that absorbs the regenerated energy of a drive as heat. Automation, controls and robotics
- Brass #
- A copper and zinc alloy that machines well and resists corrosion. Materials, manufacturing and measurement
- Brayton cycle #
- The idealized cycle of a gas turbine. Fluids, heat and thermodynamics
- Breadboard #
- A reusable board for building circuits without soldering, by pushing leads into holes. Electronics Read more: PCB Prototyping
- Break-even #
- The quantity at which the cost of one method equals the cost of another, or revenue equals cost. Math, units, quality and workshop
- Breakpoint #
- A point in a program where a debugger stops so the program state can be examined. Programming, data and computing
- Brittleness #
- The tendency of a material to break with little plastic deformation. Glass and cast iron are brittle. Mechanical design and mechanics
- Broaching #
- Cutting a shape such as a keyway with a long tool whose teeth each take a small cut in one pass. Materials, manufacturing and measurement
- Bronze #
- A copper alloy with tin (or aluminum, silicon or other elements), used for bearings, bushings and marine parts. Materials, manufacturing and measurement
- Brushless DC motor #
- A motor with permanent magnets on the rotor and electronic commutation, instead of brushes. Electrical power and machines
- Buck converter #
- A switching regulator that steps voltage down. Electronics Read more: Power and Motor Electronics
- Buckling #
- Sudden sideways collapse of a slender member under compression. Mechanical design and mechanics Read more: Columns and Buckling
- Buffer #
- A block of memory used to hold data temporarily while it is moved. Programming, data and computing
- Buffer overflow #
- Writing past the end of a buffer, which can corrupt memory and cause crashes or security holes. Programming, data and computing
- Built-up edge #
- Workpiece material that welds onto the cutting edge of a tool and spoils the surface finish. Materials, manufacturing and measurement
- Bulk modulus #
- The ratio of pressure change to the fractional volume change it causes; it measures how hard a material is to compress. Mechanical design and mechanics
- Buoyancy #
- The upward force on an object in a fluid, equal to the weight of the fluid it displaces. Fluids, heat and thermodynamics
- Busbar #
- A solid metal bar that carries large currents within a switchboard or panel. Electrical power and machines
- Bushing #
- A plain sleeve bearing, usually of bronze or plastic, pressed into a bore. Mechanical design and mechanics
- Butt weld #
- A weld joining two parts that lie in the same plane, edge to edge. Mechanical design and mechanics
- Byte #
- A group of eight bits. Programming, data and computing