Mechanical engineering spans mechanics, materials, thermodynamics, fluids, manufacturing, controls, and machine design. A complete glossary helps engineers communicate precisely, avoid ambiguity, and accelerate design and analysis. This A–Z glossary compiles core vocabulary, industry terminology, and analysis concepts used across academia and professional engineering.

🔤 A — Terms & Definitions

• Absolute Humidity — Mass of water vapor per unit volume of air.
• Absolute Pressure — Pressure measured relative to a perfect vacuum.
• Absolute Zero — Temperature at 0 K where molecular motion theoretically stops.
• Acceleration — Rate of change of velocity with time.
• Actuator — Device converting energy into mechanical motion.
• Adhesion — Attraction between dissimilar surfaces.
• Adiabatic Process — Thermodynamic process with no heat transfer.
• Aerodynamics — Study of air motion and forces on bodies in air.
• Airfoil — Shape designed to generate lift when moving through air.
• Allowable Stress — Maximum safe stress for a material in design.
• Alloy — Mixture of metals or metal + non‑metal.
• Alternator — Device generating AC electrical power.
• Amplitude — Maximum displacement in oscillatory motion.
• Anelasticity — Time‑dependent elastic behavior.
• Annealing — Heat treatment softening metals and relieving stress.
• Angular Momentum — Rotational analog of linear momentum.
• Angular Velocity — Rate of change of angular position.
• Anisotropy — Direction‑dependent material properties.
• Archimedes’ Principle — Buoyant force equals weight of displaced fluid.
• Aspect Ratio — Wing span² divided by wing area.
• Assembly — Group of components forming a functional unit.
• Axial Load — Force applied along the axis of a member.
• Axial Flow — Fluid flow parallel to the axis of rotation.
• Axisymmetric — Geometry or loading symmetric around an axis.

🔤 B — Terms & Definitions

• Backlash — Clearance between mating gear teeth.
• Back Pressure — Resistance opposing fluid flow.
• Barometer — Device measuring atmospheric pressure.
• Base Circle — Fundamental circle used in cam design.
• Bearing — Machine element supporting rotating shafts.
• Bending Moment — Internal moment causing beam bending.
• Bernoulli’s Equation — Energy conservation in fluid flow.
• Bimetallic Strip — Two metals bonded to bend with temperature.
• Biomechanics — Application of mechanics to biological systems.
• Boiler — Device generating steam or hot water.
• Bolted Joint — Mechanical fastening using bolts and nuts.
• Boundary Layer — Thin fluid layer near a surface with velocity gradient.
• Brinell Hardness — Hardness measured by indentation with a steel ball.
• Buckling — Sudden lateral instability under compressive load.
• Bulk Modulus — Resistance to uniform compression.
• Burnishing — Surface finishing by plastic deformation.
• Bypass Ratio — Ratio of bypass air to core air in jet engines.

🔤 C — Terms & Definitions

• CAD (Computer‑Aided Design) — Software for creating engineering models.
• CAE (Computer‑Aided Engineering) — Simulation tools for analysis (FEA, CFD).
• Cam — Rotating element converting rotation to reciprocation.
• Camshaft — Shaft controlling valve timing in engines.
• Capacitance — Ability to store electric charge.
• Carburetor — Device mixing air and fuel in older engines.
• Casting — Manufacturing process pouring molten metal into molds.
• Catalyst — Substance accelerating chemical reactions.
• Cavitation — Vapor bubble formation causing damage in pumps/propellers.
• Center of Gravity — Point where weight is concentrated.
• Center of Pressure — Point where aerodynamic forces act.
• Centrifugal Force — Apparent outward force in rotating frames.
• Centripetal Force — Force directing objects toward rotation center.
• CFD (Computational Fluid Dynamics) — Numerical simulation of fluid flow.
• Chamfer — Angled edge on a part.
• Cladding — Bonding a protective metal layer to a substrate.
• Clearance Fit — Fit where parts always have space between them.
• Closed‑Loop Control — Control system using feedback.
• Coefficient of Friction — Ratio describing frictional resistance.
• Coefficient of Thermal Expansion — Material expansion per degree temperature change.
• Combustion — Exothermic reaction releasing heat.
• Compressor — Machine increasing gas pressure.
• Compression Ratio — Ratio of max to min cylinder volume.
• Compressive Strength — Maximum compressive stress before failure.
• Conduction — Heat transfer through solids.
• Convection — Heat transfer via fluid motion.
• Corrosion — Material degradation due to chemical reactions.
• Creep — Time‑dependent deformation under constant load.
• Critical Speed — Speed at which rotating shafts resonate.
• Cryogenics — Study of materials at extremely low temperatures.
• Cycle — Sequence of processes returning a system to initial state.
• Damping — Energy dissipation in vibrating systems.
• Damping Ratio — Measure of how oscillations decay after disturbance.
• Dead Load — Permanent static load on a structure.
• Dead Center — Piston position at extreme ends of stroke.
• Decibel — Logarithmic unit measuring sound intensity.
• Deflection — Displacement of a structural element under load.
• Deformation — Change in shape due to applied forces.
• Density — Mass per unit volume.
• Design Factor — Ratio of strength to expected load.
• Detonation — Abnormal combustion causing shock waves.
• Diesel Cycle — Thermodynamic cycle for diesel engines.
• Diffuser — Device increasing pressure by slowing fluid.
• Diffusion — Movement of particles from high to low concentration.
• Digital Twin — Virtual model mirroring a physical system.
• Dilatation — Volumetric strain in materials.
• Direct Stress — Stress normal to a surface.
• Displacement — Change in position of a point or body.
• Dissipation — Conversion of mechanical energy to heat.
• Divergence — Measure of fluid expansion or compression.
• Ductility — Ability to deform plastically before fracture.
• Dynamic Load — Load varying with time.
• Dynamics — Study of forces and motion.
• 🔤 E — Terms & Definitions
• Eccentricity — Offset between geometric center and axis.
• Eddy Current — Circulating currents induced in conductors.
• Efficiency — Ratio of useful output to input energy.
• Elastic Limit — Maximum stress before permanent deformation.
• Elasticity — Ability to return to original shape after load removal.
• Elongation — Increase in length under tension.
• Embrittlement — Loss of ductility due to environmental effects.
• Enthalpy — Total heat content of a system.
• Entropy — Measure of disorder; increases in spontaneous processes.
• Equilibrium — State where net forces and moments are zero.
• Euler Buckling — Column instability under axial compression.
• Exergy — Maximum useful work obtainable from a system.
• Expansion Ratio — Ratio of final to initial volume in engines.
• External Combustion — Heat added outside the working fluid (e.g., steam engines).
• Extrusion — Process forcing material through a die.
• 🔤 F — Terms & Definitions
• Factor of Safety — Margin between design load and failure load.
• Fatigue — Failure due to repeated cyclic loading.
• Fatigue Limit — Stress below which a material can endure infinite cycles.
• FEA (Finite Element Analysis) — Numerical method dividing structures into elements for analysis.
• Feed Rate — Tool advance per revolution or per minute.
• FEM (Finite Element Method) — Mathematical basis of FEA.
• Ferrofluid — Magnetic liquid responding to magnetic fields.
• Fission — Splitting of heavy nuclei releasing energy.
• Flame Speed — Rate at which a flame front propagates.
• Flange — Rim or collar for strength or attachment.
• Flash Point — Lowest temperature at which vapors ignite.
• Flow Rate — Volume or mass of fluid passing per unit time.
• Fluid Mechanics — Study of fluids at rest and in motion.
• Fluidity — Ability of molten metal to fill a mold.
• Flywheel — Rotating mass storing kinetic energy.
• Force — Interaction causing acceleration.
• Forming — Shaping material without removing mass.
• Four‑Stroke Cycle — Intake, compression, power, exhaust sequence.
• Friction — Resistance to motion between surfaces.
• Friction Welding — Joining metals using heat from friction.
• Froude Number — Dimensionless number comparing inertia to gravity.
• Gage Pressure — Pressure measured relative to atmospheric pressure.
• Galvanic Corrosion — Corrosion caused by electrical contact between dissimilar metals.
• Gasification — Conversion of solid fuel into combustible gas.
• Gas Turbine — Engine using compressed air and combustion to produce shaft power.
• Gate Valve — Valve using a sliding gate to control flow.
• Gear — Toothed component transmitting torque between shafts.
• Gear Ratio — Ratio of rotational speeds between two gears.
• Gearbox — Mechanism providing selectable gear ratios.
• Gibbs Free Energy — Thermodynamic potential predicting spontaneity.
• Gimbal — Pivoted support allowing rotation in multiple axes.
• GPM (Gallons per Minute) — Common volumetric flow rate unit.
• Gradient — Vector of partial derivatives indicating direction of steepest increase.
• Grain Structure — Arrangement of crystals in a metal.
• Granular Flow — Behavior of particulate solids behaving like fluids.
• Graphitization — Transformation of carbon into graphite at high temperature.
• Gravity Casting — Metal casting using gravity to fill molds.
• Grinding — Abrasive machining for fine surface finish.
• Gyroscope — Device maintaining orientation via angular momentum.
• 🔤 H — Terms & Definitions
• Hardenability — Ability of steel to harden through thickness.
• Hardness — Resistance to indentation or scratching.
• Heat Capacity — Heat required to raise temperature of a substance.
• Heat Exchanger — Device transferring heat between fluids.
• Heat Flux — Rate of heat transfer per unit area.
• Heat of Fusion — Heat required to melt a solid.
• Heat of Vaporization — Heat required to vaporize a liquid.
• Heat Sink — Component dissipating heat from devices.
• Helical Gear — Gear with angled teeth for smoother operation.
• Helmholtz Resonance — Acoustic resonance in cavities.
• Hertzian Stress — Contact stress between curved surfaces.
• Honing — Abrasive finishing for precise bore geometry.
• Hooke’s Law — Stress proportional to strain in elastic region.
• Horsepower — Unit of power equal to 746 W.
• Hydraulic Diameter — Characteristic length for non‑circular ducts.
• Hydraulic Press — Machine using fluid pressure to apply force.
• Hydraulics — Study of liquid pressure and flow.
• Hydrodynamics — Fluid motion in liquids.
• Hydrostatic Pressure — Pressure due to fluid weight at depth.
• Hysteresis — Lag between input and response in materials or systems.
• 🔤 I — Terms & Definitions
• Ideal Gas — Hypothetical gas obeying PV = nRT exactly.
• Ignition Delay — Time between fuel injection and combustion start.
• Impact Strength — Ability to resist sudden loads.
• Impingement — Direct striking of fluid on a surface.
• Impulse — Change in momentum due to applied force over time.
• Incompressible Flow — Fluid flow with negligible density change.
• Indicated Power — Power developed inside engine cylinders.
• Induction Hardening — Surface hardening using electromagnetic heating.
• Inertia — Resistance to change in motion.
• Inertial Frame — Reference frame not accelerating.
• Inlet Manifold — Duct distributing air/fuel to cylinders.
• Injection Molding — Manufacturing process injecting molten material into molds.
• Insulation — Material reducing heat transfer.
• Intercooler — Heat exchanger cooling compressed air.
• Internal Combustion Engine — Engine where fuel burns inside the working fluid.
• Interference Fit — Fit where parts are dimensionally overlapping.
• Isentropic Process — Constant‑entropy, reversible adiabatic process.
• Isochoric Process — Constant‑volume thermodynamic process.
• Isothermal Process — Constant‑temperature thermodynamic process.
• Isotropic Material — Material with identical properties in all directions.
• Jacobian Matrix — Matrix of partial derivatives used in kinematics and nonlinear analysis.
• Jet Engine — Air‑breathing engine producing thrust via high‑velocity exhaust.
• Jet Pump — Pump using fluid momentum to entrain and move another fluid.
• Jig — Work‑holding device guiding tools for repeatability.
• Journal Bearing — Bearing supporting radial loads on rotating shafts.
• Joule — SI unit of energy equal to 1 N·m.
• Joule–Thomson Effect — Temperature change during gas expansion without heat exchange.
• Judder — Vibration or shaking in braking or clutch systems.
• Jump Conditions — Discontinuity relations across shock waves.
• 🔤 K — Terms & Definitions
• Kalman Filter — Algorithm estimating system states from noisy measurements.
• Kinematic Chain — Assembly of links connected by joints.
• Kinematics — Study of motion without considering forces.
• Kinetic Energy — Energy of motion $\frac{1}{2}m{v}^2$.
• Kinetic Friction — Friction between surfaces in relative motion.
• Knock (Engine Knock) — Abnormal combustion causing pressure spikes.
• Knurling — Machining process creating textured grip patterns.
• K‑Factor (Sheet Metal) — Ratio locating neutral axis during bending.
• K‑Value (Thermal Conductivity) — Material’s thermal conductivity coefficient.
• Kutta Condition — Aerodynamic requirement ensuring smooth flow at trailing edges.
• 🔤 L — Terms & Definitions
• Lagrangian Mechanics — Energy‑based formulation of motion.
• Laminar Flow — Smooth, orderly fluid motion in layers.
• Lap Joint — Overlapping joint used in welding and fastening.
• Latent Heat — Heat absorbed or released during phase change.
• Lateral Load — Load applied perpendicular to a structure’s axis.
• Lattice Structure — Repeating geometric framework used in lightweight design.
• Leakage — Unintended fluid escape from a system.
• Lean Mixture — Air–fuel mixture with excess air.
• Lift — Aerodynamic force perpendicular to flow direction.
• Limit Load — Maximum load a structure can sustain without permanent deformation.
• Linearity — Proportional input–output relationship.
• Linkage — Mechanism transmitting motion through connected links.
• Liquidus — Temperature above which a metal is fully liquid.
• Lithography — Patterning process used in micro‑manufacturing.
• Load Cell — Sensor converting force into electrical signal.
• Load Factor — Ratio of applied load to design load.
• Logarithmic Decrement — Measure of damping in oscillatory systems.
• Longitudinal Stress — Stress parallel to the axis of a member.
• Lubrication — Application of substances to reduce friction and wear.
• Lug — Projection used for alignment or fastening.
• Mach Number — Ratio of object speed to speed of sound.
• Machine Design — Engineering discipline focused on creating mechanical systems.
• Macrostructure — Large‑scale structural features visible to the naked eye.
• Magnetostriction — Change in material dimensions under magnetic field.
• Manifold — Channel distributing fluids to multiple paths.
• Mass Flow Rate — Mass of fluid passing per unit time.
• Material Fatigue — Failure due to repeated cyclic loading.
• Mechanical Advantage — Ratio of output force to input force.
• Mechanical Efficiency — Ratio of useful mechanical output to input.
• Mechanism — Assembly converting motion or force.
• Melting Point — Temperature at which a solid becomes liquid.
• Meshing — Engagement of gear teeth during rotation.
• Microstructure — Fine‑scale structure visible under microscope.
• Modulus of Elasticity — Ratio of stress to strain in elastic region.
• Modulus of Rigidity — Shear modulus describing resistance to shear.
• Moment — Tendency of a force to cause rotation.
• Moment of Inertia — Resistance to angular acceleration.
• Momentum — Product of mass and velocity.
• Motor Torque — Rotational force produced by a motor.
• Multiphase Flow — Flow involving multiple fluid or solid phases.
• 🔤 N — Terms & Definitions
• Natural Convection — Fluid motion driven by density differences.
• Natural Frequency — Frequency at which a system vibrates freely.
• Neutral Axis — Line in a beam experiencing zero stress during bending.
• Newton’s Laws — Fundamental laws governing motion and forces.
• Newtonian Fluid — Fluid with constant viscosity independent of shear rate.
• Nozzle — Device accelerating or decelerating fluid flow.
• NPSH (Net Positive Suction Head) — Measure of pump inlet pressure to avoid cavitation.
• Nucleate Boiling — Boiling regime with vapor bubbles forming at surface.
• Nusselt Number — Dimensionless number describing convective heat transfer.
• Nyquist Stability Criterion — Control theory method for assessing system stability.
• 🔤 O — Terms & Definitions
• Octane Rating — Measure of fuel resistance to engine knock.
• Offset — Intentional displacement between components or axes.
• Ohmic Heating — Heat generated by electrical resistance.
• Open‑Loop Control — Control system without feedback.
• Operating Point — Steady‑state condition of a system.
• Optimization — Process of improving design performance under constraints.
• Orifice — Opening controlling fluid flow rate.
• Orthotropic Material — Material with three mutually perpendicular planes of symmetry.
• Oscillation — Repetitive variation around an equilibrium point.
• Overhung Load — Load applied beyond a support or bearing.
• Overpressure — Pressure exceeding normal operating limits.
• Oxidation — Chemical reaction involving oxygen, often causing corrosion.
• Ozone Cracking — Rubber degradation due to ozone exposure.
• Pascal — SI unit of pressure equal to 1 N/m².
• Pascal’s Law — Pressure applied to a confined fluid is transmitted equally in all directions.
• Peak Pressure — Maximum pressure reached during a thermodynamic or combustion cycle.
• Pelton Wheel — Impulse turbine used for high‑head hydro power.
• Phase Diagram — Graph showing material phases under different temperatures and pressures.
• Phase Lag — Delay between input and output in oscillatory systems.
• Pinion — Smaller gear in a gear pair.
• Pitch Circle Diameter — Diameter of the imaginary circle where gear teeth effectively mesh.
• Piston — Reciprocating component transferring gas pressure to mechanical motion.
• Pitting — Localized corrosion forming small cavities.
• Plastic Deformation — Permanent shape change after stress exceeds yield point.
• Plug Flow — Idealized flow with uniform velocity across the cross‑section.
• Poisson’s Ratio — Ratio of lateral strain to axial strain.
• Polar Moment of Inertia — Resistance to torsional deformation.
• Polytropic Process — Thermodynamic process following $P{V}^n=\text{constant}$.
• Porosity — Fraction of void space in a material.
• Powertrain — System transmitting power from engine to wheels.
• Pressure Drop — Reduction in pressure due to friction or obstruction.
• Preload — Initial tension applied to bolts or bearings.
• Prismatic Joint — Joint allowing linear sliding motion.
• Prony Brake — Device measuring torque via friction.
• Psychrometrics — Study of moist air properties.
• 🔤 Q — Terms & Definitions
• Quadrature — Signals 90° out of phase, used in sensors and controls.
• Quality Factor (Q‑Factor) — Measure of damping in oscillatory systems.
• Quasi‑Static Process — Process occurring slowly enough to maintain equilibrium.
• Quenching — Rapid cooling to harden metals.
• Quick‑Return Mechanism — Mechanism with unequal forward and return stroke times.
• Quill Shaft — Hollow shaft used to reduce weight or allow internal components.
• 🔤 R — Terms & Definitions
• Radiation Heat Transfer — Heat transfer via electromagnetic waves.
• Radial Load — Load applied perpendicular to a shaft’s axis.
• Rankine Cycle — Thermodynamic cycle used in steam power plants.
• Rarefaction — Region of low pressure in a propagating wave.
• Refrigeration Cycle — Cycle transferring heat from low to high temperature.
• Refractory Material — Material resistant to high temperatures.
• Reheat Cycle — Steam cycle improving efficiency by reheating steam between turbine stages.
• Reinforcement — Material added to strengthen composites.
• Relative Humidity — Ratio of actual vapor content to saturation vapor content.
• Reliability — Probability a system performs without failure.
• Residual Stress — Stress remaining after manufacturing or loading.
• Resilience — Ability to absorb energy elastically.
• Resistance Welding — Welding using heat from electrical resistance.
• Resonance — Large amplitude vibration when frequency matches natural frequency.
• Reynolds Number — Dimensionless number predicting laminar or turbulent flow.
• Rheology — Study of flow and deformation of materials.
• Rivet — Permanent mechanical fastener.
• Rolling Resistance — Force resisting motion of rolling objects.
• Root Mean Square (RMS) — Effective value of varying quantities like vibration or current.
• Rotordynamics — Study of rotating machinery behavior.
• RPM (Revolutions per Minute) — Rotational speed unit.
• Runout — Deviation from true rotation due to misalignment or wear.
• Safety Factor — Ratio of maximum strength to expected load.
• Sand Casting — Metal casting using sand molds.
• Scramjet — Supersonic combustion ramjet engine.
• Seebeck Effect — Voltage generated by temperature differences in conductors.
• Shear Force — Force causing sliding between material layers.
• Shear Modulus — Material resistance to shear deformation.
• Shear Stress — Stress parallel to a surface.
• Shock Wave — Sudden pressure rise in supersonic flow.
• Shrink Fit — Assembly using thermal expansion/contraction for interference.
• Sintering — Bonding powder particles by heat below melting point.
• Slip — Relative motion between contacting surfaces.
• Slip Ratio — Difference between wheel speed and vehicle speed.
• Slurry — Mixture of solid particles suspended in liquid.
• Solenoid — Electromagnetic actuator producing linear motion.
• Specific Heat — Heat required to raise temperature of unit mass.
• Specific Weight — Weight per unit volume.
• Spectral Analysis — Frequency‑domain study of vibration signals.
• Spline — Grooved shaft for torque transmission.
• Spring Constant — Stiffness of a spring.
• Stagnation Pressure — Pressure when fluid is brought to rest isentropically.
• Static Equilibrium — Condition where net forces and moments are zero.
• Steam Turbine — Turbine driven by expanding steam.
• Strain — Deformation per unit length.
• Strain Energy — Energy stored due to deformation.
• Stress — Internal force per unit area.
• Stress Concentration — Localized stress increase due to geometry.
• Supercharger — Compressor increasing engine intake pressure.
• Superheated Steam — Steam heated above saturation temperature.
• Surface Finish — Texture and smoothness of a machined surface.
• Surge — Instability in compressors causing flow reversal.
• Swirl — Rotational motion in fluid flow.
• 🔤 T — Terms & Definitions
• Tachometer — Device measuring rotational speed.
• Tensile Strength — Maximum stress a material withstands in tension.
• Thermal Conductivity — Rate of heat transfer through a material.
• Thermal Expansion — Increase in size due to temperature rise.
• Thermal Fatigue — Failure due to repeated temperature cycling.
• Thermal Resistance — Opposition to heat flow.
• Thermodynamic Cycle — Sequence of processes returning a system to initial state.
• Thermostat — Device regulating temperature.
• Thrust — Force propelling an object forward.
• TIG Welding — Tungsten inert gas welding process.
• Torque — Rotational equivalent of force.
• Torsion — Twisting of a structural member.
• Total Pressure — Sum of static and dynamic pressure.
• Toughness — Ability to absorb energy before fracture.
• Turbine — Machine extracting energy from fluid flow.
• Turbulence — Chaotic, irregular fluid motion.
• Turbocharger — Turbine‑driven compressor boosting engine power.
• Turning — Machining process removing material with a lathe.
• 🔤 U — Terms & Definitions
• Ultimate Strength — Maximum stress a material can withstand.
• Ultrasonic Testing — Nondestructive testing using high‑frequency sound waves.
• Uncertainty — Range within which the true value is expected.
• Underexpanded Jet — Jet where exit pressure exceeds ambient pressure.
• Understeer — Vehicle turning less than commanded.
• Uniform Flow — Flow with constant velocity at all points.
• Unsteady Flow — Flow where properties change with time.
• U‑Value — Overall heat transfer coefficient.
• Upstream — Direction opposite to fluid flow.
• U‑Tube Manometer — Device measuring pressure differences using liquid columns.
• Utilization Factor — Ratio of actual output to rated capacity.
• Vacuum Pressure — Pressure lower than atmospheric pressure.
• Valve — Device regulating fluid flow.
• Valve Timing — Coordination of valve opening/closing in engines.
• Vapor Pressure — Pressure exerted by a vapor in equilibrium with its liquid.
• Vaporization — Phase change from liquid to vapor.
• Vector — Quantity with magnitude and direction.
• Velocity — Rate of change of displacement.
• Venturi Effect — Pressure drop in a constricted fluid passage.
• Vibration — Oscillatory motion about an equilibrium point.
• Viscosity — Fluid resistance to shear or flow.
• Viscous Damping — Damping proportional to velocity.
• Void Ratio — Ratio of void volume to solid volume in porous materials.
• Volumetric Efficiency — Ratio of actual to theoretical intake air volume in engines.
• Von Mises Stress — Yield criterion used in ductile material design.
• 🔤 W — Terms & Definitions
• Wankel Engine — Rotary internal combustion engine with triangular rotor.
• Wastegate — Valve controlling turbocharger boost pressure.
• Water Hammer — Pressure surge from sudden fluid stoppage.
• Watt — SI unit of power equal to 1 J/s.
• Wear — Material loss due to friction or abrasion.
• Weir — Structure measuring or controlling open‑channel flow.
• Welding — Joining process using heat, pressure, or both.
• Wet Bulb Temperature — Temperature measured by a wetted thermometer bulb.
• Whirling Speed — Critical speed causing shaft instability.
• Work — Energy transfer by force acting through distance.
• Work Hardening — Strengthening of metal by plastic deformation.
• 🔤 X — Terms & Definitions
• X‑Ray Diffraction (XRD) — Technique identifying crystal structures.
• X‑Axis — Horizontal axis in Cartesian coordinates.
• Xenon Lamp — High‑intensity discharge lamp used in optical systems.
• X‑Direction Stress — Normal stress acting along the x‑axis.
• 🔤 Y — Terms & Definitions
• Yield Point — Stress at which material begins plastic deformation.
• Yield Strength — Stress causing permanent deformation.
• Young’s Modulus — Modulus of elasticity in tension/compression.
• Yaw — Rotation about a vertical axis.
• Y‑Strainer — Filter removing debris from pipelines.
• Y‑Axis — Vertical axis in Cartesian coordinates.
• 🔤 Z — Terms & Definitions
• Zero‑Point Energy — Lowest possible energy of a quantum system.
• Zero‑Shift — Instrument calibration drift from true zero.
• Zeta Potential — Electrical potential at particle–fluid interface.
• Zinc Coating — Protective galvanizing layer preventing corrosion.
• Zirconia — High‑temperature ceramic used in sensors and coatings.
• Zone Refining — Purification method using controlled melting zones.
• Z‑Direction Stress