Engineering glossary

All finishing operations after 3D printing: support and powder removal, cleaning, post-curing, heat treatment, machining and surface finishing.

Non-contact measurement of a physical object's shape that produces a point cloud or mesh. Used for reverse engineering and dimensional inspection.

CNC machining in which the tool moves along three linear and two rotary axes relative to the part, so it can be machined from several sides in one setup.

A tough amorphous thermoplastic (acrylonitrile butadiene styrene) for housings and enclosures. Easy to mold, machine and print; good to about 80 °C.

Making parts by adding material layer by layer directly from 3D data, without molds or tooling. In everyday language it is called 3D printing.

Aluminum alloyed with magnesium, silicon, copper or zinc. At a third of steel's density, it offers good strength, machinability and corrosion resistance.

An electrochemical process that grows a hard oxide layer on aluminum. It protects against corrosion and wear and can be dyed in a range of colors.

A structured list of all parts, subassemblies, purchased items and materials, with quantities, needed to manufacture and assemble a product.

A 3D model built from parts and subassemblies positioned by mates. Used to check interference and fit, and to create the BOM and assembly drawing.

A digital 3D model of a part or assembly created in CAD software. It is the basis for drawings, manufacturing, simulation and quality inspection.

Software that turns a CAD model into toolpaths and programs for CNC machines. It lets you simulate machining and catch collisions before a part is cut.

A composite of carbon fibers in a polymer matrix, usually epoxy. It is very stiff and strong at low weight, and its properties depend on fiber orientation.

A part made by pouring or injecting molten metal into a sand, metal or ceramic mold. Suits complex shapes and larger series; functional faces are machined.

A mark by which the manufacturer declares that a product meets the applicable EU rules that require CE. Without it, the product cannot enter the EU market.

Numerical simulation of liquid and gas flow that predicts velocities, pressures, temperatures and forces inside or around a product before it is built.

Measuring a part's dimensions and geometry by probing points on its surface with a coordinate measuring machine (CMM), including geometric tolerances.

Machining of metals and plastics on computer-controlled machine tools (milling, turning, drilling). Suited to precise prototypes and production parts.

Machining with a rotating cutter (end mill) on a CNC machine to produce flat faces, pockets, slots and freeform 3D surfaces in metals and plastics.

Machining in which the workpiece rotates while a cutting tool removes material. CNC lathes make shafts, pins, bushings, flanges and other round parts.

A composite material made of layers of reinforcing fibers (carbon, glass, aramid) in a polymer matrix, with high strength and stiffness for its weight.

A repeated cycle of designing, testing and refining that moves a design step by step toward its requirements. Each round should answer a specific question.

A planned, documented review of a design at a set stage of development, where the team checks it against requirements and decides how to proceed.

A development approach that makes the target manufacturing cost a binding requirement and uses it to steer design decisions throughout the project.

Comparison of a part's measured shape, usually a 3D scan, with its nominal CAD model, giving a color deviation map and checks of dimensions and tolerances.

An approach to product design that cuts the number of parts and simplifies handling, inserting and joining them, so assembly is fast, cheap and error-free.

A design approach that accounts for the chosen manufacturing process from the start, so parts can be made reliably, at reasonable cost and without rework.

Injecting molten metal (aluminum, zinc or magnesium) at high speed and pressure into a steel die. Suited to complex thin-walled parts in high volumes.

A virtual counterpart of a specific product, machine or process that is continuously updated with real operating data and used for analysis and prediction.

A slight taper of a part's walls in the direction the mold opens, which lets a molded or cast part release without sticking, scratching or deforming.

An exchange format for 2D vector data (lines, arcs, curves, layers). Most often used as the input for laser cutting and other 2D cutting processes.

A system of tolerances and fits under ISO 286 that defines the clearance or interference between a hole and a shaft, for example H7/g6 or H7/p6.

Plastics with higher strength, stiffness, heat and chemical resistance than commodity plastics, used for load-bearing, sliding and functional parts.

The ratio of the limit a part can withstand (such as its yield strength) to the actual stress or load in service. It expresses the margin against failure.

A 3D printing method that deposits molten plastic filament layer by layer. Inexpensive and widely available, it is best suited to form and fit prototypes.

A numerical method that divides a part into a mesh of small elements and computes stresses, deformations, temperatures or natural frequencies under load.

A systematic team method that identifies potential failure modes of a product or process in advance, rates their risk and defines actions to reduce it.

A prototype that tests how a product really works (mechanism, strength, assembly, electronics), not just its look and shape, before series production.

A system of symbols and rules for specifying tolerances of form, orientation, location and runout on drawings, defined by ASME Y14.5 and ISO 1101.

Controlled heating, holding and cooling of a metal that changes its structure and with it the hardness, strength, toughness or internal stresses.

The discipline that designs the form, ergonomics, controls and appearance of mass-produced products so they are easy to use, understand and manufacture.

A precision metal tool with a cavity into which molten plastic is injected. It sets the shape, accuracy and surface of the part and is the main investment.

A process for mass-producing plastic parts by injecting molten plastic under pressure into a metal mold. The mold is costly, but the part price is low.

Thermal cutting with a focused laser beam, most often of sheet metal along a 2D contour. It is fast and accurate and needs no part-specific tooling.

A 3D scanning method that captures an object's shape with a laser line or beam, from handheld scanners for parts to long-range scanners for buildings.

Making typically tens to hundreds of parts or products with processes that need no costly tooling, such as CNC machining, 3D printing or vacuum casting.

Progressive damage caused by repeated (cyclic) loading that leads to a crack and fracture even at stresses below the material's yield strength.

Additive manufacturing of metal parts layer by layer, mostly by laser melting of metal powder. Enables internal channels, lattices and complex shapes.

The simplest version of a product that real customers can use, built to test demand and the core benefit with the smallest possible investment.

A powder bed 3D printing process in which plastic powder is fused by infrared energy wherever an agent was printed. Suits functional parts and small runs.

Structuring a product into self-contained modules with precisely defined interfaces, so they can be combined into variants, developed apart and swapped.

A contract in which a party agrees not to disclose or misuse confidential information, such as drawings, CAD data or know-how, shared during a project.

A 3D CAD method in which geometry is driven by dimensions, equations and constraints. Changing a parameter updates the model, assembly and drawings.

A system for central management of CAD models, drawings and related documents. It controls versions, revisions, access rights and change approvals.

An amorphous copolyester derived from PET. Tough, transparent and chemically resistant, easy to print and thermoform, and good up to about 60 to 65 °C.

A method that calculates the 3D position of points and the shape of an object from photos taken from several directions. Used to measure large parts.

The first limited batch of products made with production tooling and processes, used to validate quality, process and assembly before full production.

A thermoplastic (polylactic acid) made from plant sugars. Stiff and easy to print with FDM, but brittle, and it softens at only about 55 to 60 °C.

An approach and software platform for managing all product information from the first idea through development, production and service to end of life.

A large set of 3D coordinates describing the surface of a scanned object. It is the primary output of 3D scanning and the basis for further processing.

A tough semi-crystalline thermoplastic (nylon) resistant to wear, fatigue and oils. It absorbs moisture, which changes both its stiffness and dimensions.

A transparent amorphous thermoplastic with very high impact strength and heat resistance around 125 °C, used for protective glazing, covers and housings.

A representation of a 3D object's surface made of vertices and faces, usually triangles. It is the typical output of 3D scanning and input for 3D printing.

3D printing in which printheads jet droplets of photopolymer that UV light cures at once. Combines rigid and rubber-like materials and colors in one part.

Semi-crystalline engineering plastic with high stiffness, low friction and minimal moisture uptake. Easily machined into gears, bushings and precise parts.

Electrostatic application of dry powder paint to a metal part, which is then cured in an oven. It creates a tough, even coating without solvents.

A document that states in measurable terms what a product must do: functions, parameters, environment, interfaces, regulations, target cost and volume.

An early test showing that the key technical principle of a new product actually works. It answers the feasibility question before detailed development.

Planned tests on physical prototypes that verify a product's function, strength, durability, environmental resistance and ergonomics before production.

Technologies and methods for quickly making a physical prototype straight from a CAD model, usually by 3D printing or CNC machining, with no tooling.

Fast, low-cost production of molds and tools (silicone, aluminum or 3D-printed) for prototype and short runs of parts in production material.

Parts made to match an existing, often worn or damaged, original when there is no drawing for it or the original part can no longer be bought.

The process of capturing the geometry of an existing physical part and turning it into a CAD model and manufacturing drawings, typically for spare parts.

Converting 3D scan data (a point cloud or mesh) into a CAD model with exact geometry that can be edited, dimensioned and used for manufacturing.

Repeated manufacture of identical parts or products in larger quantities with molds, tooling and fixtures, lowering unit cost and ensuring repeatability.

Forming sheet metal along a straight bend line, usually on a press brake between punch and die. Turns flat blanks into profiles, enclosures and brackets.

Designing parts made from sheet by cutting and bending. It accounts for thickness, bend radii, the flat pattern and the manufacturer's tooling.

An additive process that cures photopolymer resin layer by layer with UV light. It achieves high accuracy and a smooth surface with fine detail.

An additive process in which a laser sinters nylon powder layer by layer. Parts need no supports and have good mechanical properties for functional use.

3D CAD software from Dassault Systèmes for parametric modeling of parts and assemblies, drawings and basic simulations in mechanical engineering.

Corrosion-resistant steel with at least 10.5 % chromium, which forms a protective passive layer. The most common grades are 304 (1.4301) and 316L (1.4404).

A neutral ISO 10303 format for exchanging 3D CAD geometry between systems. It uses the .step and .stp extensions and usually carries no parametric history.

A format that describes the surface of a 3D object as a mesh of triangles. The standard input for 3D printing, but with no units, color or exact surfaces.

A calculation that verifies a part or structure can carry its expected loads without permanent deformation, fracture, buckling or fatigue damage.

A 3D scanning method in which a projector casts stripe patterns onto an object and cameras calculate the surface shape from how the patterns deform.

Processes that change the surface of a part to protect it against corrosion and wear or to adjust its appearance, friction or electrical conductivity.

A 3D modeling method that builds shape from individual surfaces with zero thickness. Suited to complex styled and ergonomic parts.

The fine irregularities that manufacturing leaves on a surface. Usually given as Ra in micrometers and shown on drawings with a roughness symbol.

The drawings, 3D models, bills of materials and specifications that define a product unambiguously for manufacturing, inspection, assembly and service.

A drawing of a single part with everything needed to make and inspect it: shape, dimensions, tolerances, surface roughness, material and finish.

A scale from 1 to 9 that rates how mature a technology is, from basic principles observed to a system proven in operation. Used in R&D and grant funding.

Shaping a heated plastic sheet or film over a mold using vacuum, air pressure or a plug. Low tooling cost, well suited to large thin-walled parts.

A calculation of how the tolerances of individual dimensions add up in an assembly and affect a functional dimension such as a clearance or alignment.

The permitted deviation of a feature's size, form or position from its nominal value. It decides whether a part works and strongly affects cost.

A computational method that uses loads and supports to find the material layout with the lowest mass while keeping the required stiffness or strength.

Thermoplastic polyurethane, a flexible elastomer processed like a thermoplastic. Excellent abrasion and tear resistance; hardness from soft to rigid.

A registered right for technical inventions, granted without examining novelty. Faster and cheaper than a patent, it usually lasts at most 10 years.

Low-volume production of plastic and rubber-like parts by casting polyurethane resins into silicone molds under vacuum, using a master pattern.

Verification confirms that a product meets its specified requirements. Validation confirms that it meets the user's real needs in its intended use.

A physical model that faithfully replicates the shape, colors and surface finish of a future product but does not need to perform its technical function.

Cold cutting with a thin, very high-pressure water jet, with abrasive added for hard materials. Cuts metal, stone, glass and composites without heat.