Engineering Glossary: M
51 definitions in plain language.
51 terms beginning with M. Use the filter to narrow the list, or the letters to jump to another part of the glossary.
51 terms
- Machine epsilon #
- The smallest number that, added to 1, gives a result different from 1 in floating-point arithmetic; about 2.2E-16 for double precision. Programming, data and computing
- Machine learning #
- Methods in which computers learn patterns from data instead of being programmed with explicit rules. Programming, data and computing Read more: Machine Learning
- Machine vision #
- The use of cameras and image processing for inspection and guidance. Automation, controls and robotics
- Machining #
- Removing material from a workpiece with cutting tools. Materials, manufacturing and measurement Read more: CNC Machining
- Mach number #
- The ratio of the speed of an object or flow to the speed of sound. Fluids, heat and thermodynamics
- Magnesium alloy #
- The lightest structural metal alloys, used where weight matters; they burn if chips ignite. Materials, manufacturing and measurement
- Malleable iron #
- Cast iron that is heat treated after casting to make it more ductile. Materials, manufacturing and measurement
- Martensite #
- The very hard, brittle structure formed when steel is quenched fast enough. Materials, manufacturing and measurement
- Mass #
- The amount of matter in a body, in kilograms; it does not change with location. Math, units, quality and workshop Read more: Mass Converter
- Mass flow rate #
- The mass of fluid that passes a section per unit time, in kg/s. Fluids, heat and thermodynamics
- Mass moment of inertia #
- A body's resistance to a change in its rotation about an axis, equal to the sum of mass times distance squared. Mechanical design and mechanics
- Material safety data sheet #
- A document that gives hazards, handling and emergency information for a chemical, now called a safety data sheet (SDS). Math, units, quality and workshop
- MATLAB #
- A commercial numerical computing environment widely used in engineering. Programming, data and computing
- Matrix #
- A rectangular array of numbers used to solve systems of equations and describe transformations. Math, units, quality and workshop
- Maximum material condition #
- The condition in which a feature contains the most material, for example the smallest hole or the largest shaft; shown as M in a circle. Materials, manufacturing and measurement Read more: Modifiers and Material Conditions
- Mean #
- The average of a set of numbers: the sum divided by the count. Math, units, quality and workshop
- Mechanical advantage #
- The ratio of the output force to the input force of a machine. Mechanical design and mechanics
- Mechanism #
- An assembly of links and joints designed to transmit motion. Mechanical design and mechanics Read more: Linkages and Mechanisms
- Median #
- The middle value of a set of numbers arranged in order. Math, units, quality and workshop
- Megohmmeter #
- An instrument that applies a high voltage to measure insulation resistance; also called a megger. Electrical power and machines
- Memory leak #
- Memory that a program has allocated and no longer uses, but never gives back. Programming, data and computing
- Memory-mapped register #
- A hardware control or status register accessed like a memory location. Programming, data and computing Read more: Bitwise & Register Field Calculator
- Mesh #
- The set of small elements that a part is divided into for finite element analysis. Programming, data and computing
- Metastability #
- An unstable state of a flip-flop caused by an input changing at the clock edge; its output settles at random. Electronics
- Microcontroller #
- A small computer on a single chip, with a processor, memory and input and output pins, used in embedded devices. Programming, data and computing Read more: Embedded Systems
- Micrometer #
- A precision hand instrument that measures small lengths by the turning of a fine screw. Materials, manufacturing and measurement
- Milestone #
- A key point in a project, such as the completion of a major stage. Math, units, quality and workshop
- Milling #
- Machining with a rotating multi-tooth cutter moved against the workpiece. Materials, manufacturing and measurement
- Miner's rule #
- A rule that adds up the damage from different stress levels, each cycle count divided by the life at that stress, and predicts failure when the sum reaches 1. Mechanical design and mechanics
- Minimum viable product #
- The simplest version of a product that is good enough to test with real users. Math, units, quality and workshop
- Minor loss #
- The pressure loss in fittings, valves and changes of section, given by a loss coefficient K. Fluids, heat and thermodynamics Read more: Fitting and Valve Loss Coefficients (K Factors)
- Modbus #
- A simple serial and Ethernet protocol widely used to read and write registers in devices. Automation, controls and robotics Read more: Modbus Frame and CRC Calculator
- Mode #
- The value that occurs most often in a set of numbers. Math, units, quality and workshop
- Module #
- The pitch diameter in millimeters divided by the number of teeth; the metric measure of gear tooth size. Mechanical design and mechanics
- Modulus of elasticity #
- Another name for Young's modulus: how much stress a material needs to stretch by a given strain. Mechanical design and mechanics
- Moment #
- The turning effect of a force about a point, equal to the force times the perpendicular distance. Mechanical design and mechanics
- Moment arm #
- The perpendicular distance from the line of action of a force to the point about which its moment is taken. Mechanical design and mechanics
- Moment of force #
- Another name for a moment: force times its perpendicular distance from a point. Mechanical design and mechanics
- Momentum #
- Mass times velocity. It is conserved in a collision when no outside force acts. Mechanical design and mechanics
- Moody diagram #
- A chart of the friction factor against the Reynolds number for several relative roughness values. Fluids, heat and thermodynamics
- MOSFET #
- A metal-oxide-semiconductor field-effect transistor, controlled by gate voltage; the standard switching device. Electronics
- Motion profile #
- The planned position, speed and acceleration of a move against time, such as a trapezoidal profile. Automation, controls and robotics
- Motor control center #
- A cabinet that groups motor starters, breakers and controls together. Electrical power and machines
- Motor efficiency #
- The mechanical power out of a motor divided by the electrical power in. Electrical power and machines
- Motor starter #
- A contactor with an overload relay, used to start and protect a motor. Electrical power and machines
- MQTT #
- A lightweight publish-subscribe messaging protocol widely used for IoT data. Automation, controls and robotics
- MTBF #
- Mean time between failures: the average operating time between failures of a repairable item. Math, units, quality and workshop
- MTTF #
- Mean time to failure: the average life of an item that is not repaired. Math, units, quality and workshop
- Multimeter #
- A handheld instrument that measures voltage, current and resistance. Electronics Read more: Design, Testing and Troubleshooting
- Multiplexer #
- A circuit that selects one of several inputs and passes it to the output. Electronics
- Mutex #
- A lock that lets only one task use a shared resource at a time. Programming, data and computing