Glossary

Drawing language

47 terms

STEP

STEP is the ISO standard for exchanging 3D product data between CAD, CAM and other engineering systems.

STEP AP242

The current STEP application protocol, built to carry a model-based product definition, geometry plus PMI, rather than geometry alone.

B-rep

A solid represented by its bounding faces, edges and vertices, rather than by voxels or a triangulated surface.

PMI

Product and Manufacturing Information: tolerances, datums and other manufacturing requirements attached to a 3D model as structured data, not only as text on a drawing.

GD&T

Geometric Dimensioning and Tolerancing: a symbolic language for saying what a dimension actually needs to control, not just how big a feature is.

Model-Based Definition (MBD)

Using a digital 3D model, not a 2D drawing, as the primary carrier of a part's product-definition information.

CAD

The 3D model a factory actually works from, not the 2D drawing on top of it.

3D CAD

A three-dimensional solid or surface model, as opposed to a flat, two-dimensional drawing.

Topology

How a part's faces, edges and vertices connect to each other, independent of their exact size or position.

Face

One bounded surface of a part's 3D model, the basic building block of a boundary representation.

Edge

The boundary curve where two faces of a part's 3D model meet.

Dimensional tolerance

The allowed variation on a single linear or angular dimension, as opposed to a geometric tolerance on form, orientation or location.

Geometric tolerance

A tolerance on form, orientation, location or runout, controlled independently of a part's size.

Material specification

The exact material grade, standard and condition a part must be made from, not just a generic material name.

Revision

A tracked, dated version of a part's drawing or model, and the reference point every quote and routing is tied to.

Thin wall

A wall thin enough relative to its height or the forces on it that it can deflect, vibrate or distort during machining.

Tool accessibility

Whether a specific tool, at a specific length, can reach a feature without the tool holder or spindle colliding with the part.

Stock

The raw material a part starts as, before any material is removed to reach the finished geometry.

Material removal

The general term for cutting away stock material to reach a part's finished geometry, as opposed to adding or forming material.

Hole

A cylindrical cavity through or into a part, one of the most common manufacturing features.

Pocket

A recessed cavity milled into a part, bounded by walls and a floor, open at the top.

Slot

A long, narrow channel milled into a part, open at one or both ends or fully enclosed.

Chamfer

A flat, angled edge break, replacing a sharp corner with a small angled surface.

Fillet

A rounded, curved edge break, replacing a sharp corner with a smooth radius.

Geometry model

The specific digital representation of a part's shape that a piece of software actually operates on, such as a B-rep or a mesh.

Diameter (⌀)

A circular feature gets its size as a diameter, not a radius.

Plus/minus tolerance (±)

A dimension without an allowed deviation does not exist: that deviation has a limit.

Perpendicularity (⟂)

Square by eye is not the same as square against a reference plane.

Angularity (∠)

Any angle that is not ninety degrees carries its own tolerance symbol.

Position (⌖)

A hole is never exactly where the drawing says, position tolerance says how far that may drift.

Cylindricity (⌭)

A shaft can measure the right diameter everywhere and still be bent, barrel-shaped or skewed.

Flatness (⏥)

A flat surface says nothing about where it sits, only about how flat it is.

Circularity (○)

Circularity looks at one cross-section, not the whole length of a shaft.

Symmetry (⌯)

What looks centred is not always symmetric under measurement.

Total runout (⌰)

A single full rotation catches every form and position error at once.

Datum

A datum is the plane, axis or point that the other measurements on the part are taken from.

Feature control frame

A feature control frame states in one line which geometric requirement applies, how tight it is, and what it is measured from.

Basic dimension

A basic dimension carries no tolerance of its own; the tolerance sits in the feature control frame that refers to it.

Surface roughness (Ra, Rz)

Ra and Rz say how smooth a surface has to be, and with that often whether a finishing operation follows the cut.

First article inspection

A standardised process that verifies a production process can realise a defined product, evidenced with a full check of a representative first part.

CMM (coordinate measuring machine)

A coordinate measuring machine probes points on a part and compares them with what the drawing requires.

General tolerance (ISO 2768)

The general tolerance covers any dimension with no tolerance of its own, and usually sits in or beside the title block.

Thread callout

A thread callout states which thread type, size and pitch a hole or shaft has to get.

STEP vs. STL

STEP preserves exact, editable geometry and product data; STL is a rough triangulated approximation with no such data.

CAD vs. CAM

CAD defines what a part is; CAM decides how a specific machine will actually cut it.

PMI vs. drawing

PMI embeds requirements directly in the 3D model; a drawing communicates them as a separate 2D document.

Material certificate

A document from a material supplier certifying the actual composition and properties of a specific material lot.

Processes

68 terms

Part requirement

Everything a part must satisfy to be accepted, beyond the geometry that shows what it should look like.

Feature recognition

Automatically identifying manufacturing features, such as pockets and holes, directly from a 3D CAD model.

Accessibility

Whether a cutting tool can physically reach a feature without colliding with the rest of the part or the fixture.

Design for Manufacturing

Designing a part so it is easier and cheaper to make, without necessarily changing what it needs to do.

B-rep learning

Applying machine learning directly to a part's boundary representation (B-rep), rather than converting it to a mesh or point cloud first.

Geometry foundation model

A hypothetical large, broadly pretrained model for 3D geometry, analogous to a language foundation model, applied to CAD data.

Manufacturing feature

A region of geometry with manufacturing meaning, such as a pocket or a hole, not just a face or an edge.

Manufacturability

Whether a part, with its specific requirements, can actually be produced, not just whether its geometry is valid.

Process planning

Determining the sequence of operations, machines and resources needed to turn a part's requirements into a manufactured part.

Machine selection

Choosing which specific machine will run an operation, not just which process family it belongs to.

Setup

How a part is positioned and held for an operation, and everything that changes when it has to be repositioned.

Machine capability

What a specific machine can actually and reliably achieve, not just whether a part fits its work envelope.

Factory capability

The combined set of machines, tooling, people and process knowledge that determines what a specific factory can reliably produce.

Programming time

The time spent preparing the CAM program and tool path before the machine ever runs, priced separately from cycle time.

Milling

Setups and tool changes often decide more of the cycle time than the cut itself.

Turning

Turned profiles and grooves are comparatively predictable to estimate.

EDM

A process that removes material with controlled electrical sparks instead of a cutting edge.

Wire EDM

A thin, continuously fed wire electrode cuts a profile through a conductive workpiece, one path at a time.

CNC machining

Computer-controlled cutting, where a program, not a hand on a handwheel, drives the tool's motion.

3-axis machining

Cutting with linear motion along three axes (X, Y, Z), the baseline capability most milling machines have.

3+2 machining

Tilting the part to a fixed angle between cuts, then machining with ordinary 3-axis motion at each position.

Cutting speed

How fast the cutting edge moves through the material, one of the core parameters that sets machining time and tool life.

Feed rate

How fast the tool advances into the material per revolution or per minute, alongside cutting speed one of the two core cutting parameters.

Chip load

The thickness of material each cutting edge removes per pass, a key parameter for tool life and chip evacuation.

Depth of cut

How much material is removed in a single pass, measured perpendicular to the direction of feed.

Width of cut

How much of the tool's diameter engages the material radially, alongside depth of cut a core roughing parameter.

Tool deflection

How much a cutting tool bends under cutting force, a key limit on accuracy for long or thin tools.

Tool wear

The gradual degradation of a cutting edge with use, eventually requiring the tool to be replaced or reground.

Fixture

The physical device that holds a part in a known position during machining, as distinct from the act of using it.

Tooling

The cutting tools, holders and related equipment a shop needs to produce a part, beyond the machine itself.

Sinker EDM

Shaping a cavity by plunging a formed electrode into a hardened conductive workpiece, the mirror image of wire EDM.

Hole EDM

Drilling small, precise holes with a fast-spinning tubular electrode and controlled sparks, reaching hardened materials a twist drill cannot.

Laser cutting

Cutting sheet material with a focused, high-power laser beam instead of a mechanical blade or punch.

Bending

Forming a flat sheet metal part along a straight line by plastically deforming it, rather than removing material.

Assembly

Combining multiple manufactured parts into a finished product, a distinct activity and cost from producing any one part.

ECM (electrochemical machining)

Removing material through controlled electrochemical dissolution, the reverse of electroplating, rather than a cutting edge or sparks.

Computer-aided process planning (CAPP)

Software that assists or automates deciding how to manufacture a part, connecting CAD design data to CAM manufacturing preparation.

Manufacturing route

Another common name for the ordered sequence of operations, machines and setups a part goes through, often used interchangeably with routing.

Manufacturing cost

The total cost to produce a part, combining material, machine time, setup, tooling and overhead, not just the cutting itself.

Manufacturing plan

The overall plan for how, when and where a part will be produced, broader than a single process plan.

Process plan

The specific, technical output of process planning: which operations, in what order, on which machines, for a given part.

Operation

A single, distinct manufacturing step, such as one milling pass or one turning cut, the basic unit a routing is built from.

Operation sequence

The order in which a part's operations are performed, which can change what's achievable and how much it costs.

Work preparer

The person who translates a part's drawing and requirements into a concrete routing: operations, machines, tooling and setups.

Manufacturing engineer

An engineering role focused on how a part is actually produced, often bridging design and the shop floor.

Estimator

The person (calculator) who turns a part's requirements and routing into a cost and price, before production ever starts.

Repeat order

An order for a part that has been made before, where the routing, tooling and estimate largely already exist.

Revision order

An order for a part that has changed since it was last made, somewhere between a repeat order and an entirely new one.

Make-or-buy

The decision of whether to manufacture a part or operation in-house, or purchase it or outsource it elsewhere.

Purchased part

A part or component bought ready-made from a supplier, rather than manufactured in-house.

Outsourcing

Sending a specific operation to another supplier, while the rest of a part's production stays in-house.

Post-processing

A finishing operation applied after a part's main machining is done, such as deburring, coating, or heat treatment.

Cycle time vs. lead time

Cycle time is how long a machine actually takes to make one part; lead time is how long a customer waits to receive it.

Pre-calculation vs. post-calculation

Pre-calculation predicts what a part should cost before it's made; post-calculation checks what it actually cost afterward.

Work preparer vs. CNC programmer

A work preparer decides the overall routing; a CNC programmer writes the specific program for one machine and operation.

3+2 vs. simultaneous 5-axis

3+2 tilts the part to a fixed angle then cuts with 3-axis motion; simultaneous 5-axis moves all five axes together during the cut.

Wire EDM vs. sinker EDM

Wire EDM cuts a through profile with a moving wire; sinker EDM shapes a closed cavity by plunging a formed electrode.

Grinding

The last micron is often a different process from the first millimetre.

Sheet metal

A sheet asks for a different cost logic than a block of material.

Welding

A weld rarely appears on a part drawing, usually on the assembly drawing.

Five-axis machining

In five-axis machining two rotary axes move alongside the three linear axes, so more faces are reachable in one setup.

Mill-turn

A mill-turn machine turns and mills a part in one setup, so it comes off the machine complete.

Setup time and run time

Setup time falls once per order, run time falls per part; that difference decides how the price moves with batch size.

Fixturing

The fixture holds the workpiece and decides which faces are reachable and how accurately they come out.

Tool path

A tool path is the route the cutting tool follows through the material, and that route sets a large part of the machining time.

Material removal rate

The material removal rate is how much material a tool takes away per unit of time, usually given in cubic centimetres per minute.

Cycle time

Cycle time is the time one part takes on one machine, from loading to unloading.

Lead time

Lead time is the time between order and delivery, and most of it is waiting rather than machining.

Shop and ERP

39 terms

Digital thread

A traceable, connected chain of data linking a part from its engineering definition through manufacturing to its as-built record.

Pre-calculation

The estimate made before production starts: which operations, how long they take, and what they should cost.

Production actuals

Recorded production data such as actual cycle time, but real is not the same as representative for training a model.

CAM

Software that turns a chosen process plan into the actual toolpaths and NC code a CNC machine executes.

Digital twin

A predictive model of a specific physical system, built from real data, used to mirror and forecast its behavior.

NC code

The machine-readable program, typically G-code, that tells a CNC machine exactly how to move to produce a part.

Postprocessor

The software translator that converts a generic CAM toolpath into the exact NC code syntax a specific machine's controller requires.

Metrology

The science and practice of measurement, underlying every inspection method used to verify a part meets its requirements.

PDM (product data management)

Software that manages CAD files and their versions, a narrower scope than the broader product lifecycle PLM covers.

CPQ (configure, price, quote)

Software that automates generating a price and quote from a defined set of configuration options, common for standardized products.

Tool management

Tracking a shop's cutting tools, their location, condition and remaining life, so the right tool is available when needed.

CAM vs. CNC

CAM is the software that plans toolpaths; CNC is the machine control method that executes them.

ERP vs. MES

ERP manages orders, stock and administration; MES drives and records what actually happens on the shop floor.

Digital thread vs. digital twin

A digital thread is the traceable data connection across a system's life; a digital twin is a predictive model built using that data.

Inspection

Checking a part against its requirements after (or during) production, using measurement to confirm conformance.

Measurement

The act of determining a specific physical quantity, such as a dimension, using an instrument, the basic building block of inspection.

AS9102

The aerospace industry standard defining what a First Article Inspection Report must contain and how it must be conducted.

Traceability

The ability to trace a part back to its material, process history and inspection records, often required for regulated industries.

Nonconformance

A part or condition that doesn't meet its specified requirements, formally documented through a nonconformance report (NCR).

Scrap

A part rejected as unusable, discarded rather than reworked, representing a total loss of the material and time invested.

Rework

Correcting a nonconforming part to bring it into compliance, rather than discarding it as scrap.

Process capability

A statistical measure of how consistently a process can produce parts within a specified tolerance, not just whether it can occasionally hit it.

Actual cycle time

The cycle time genuinely measured during a production run, as opposed to the estimated or theoretical cycle time.

Outlier

A measured or recorded value that differs significantly from the expected pattern, which may indicate a real problem or just noise.

Variation

The natural spread in measured values a process produces, even when nothing is going wrong.

Deviation

A formally approved departure from a part's specified requirements, agreed upon before or after the fact, distinct from an unauthorized nonconformance.

Inspection evidence

The documented proof, measurements, reports, certificates, that a part actually met its requirements, not just a claim that it did.

Work preparation

Work preparation turns a drawing into a workable plan: which operations, in what order, on which machine, with which tooling.

Routing

A routing is the list of operations a part goes through, in order, with a machine and a time for each step.

Bill of materials

A bill of materials says which parts and materials a product is made from, and in what quantities.

ERP in manufacturing

An ERP system keeps a company's orders, stock, purchasing, hours and invoices in one administration.

MES (manufacturing execution system)

An MES drives and records what happens on the shop floor: which order runs on which machine, and for how long.

PLM (product lifecycle management)

A PLM system manages product data and its revisions: which drawing, which bill of materials and which version belong together.

RFQ (request for quotation)

A request for quotation is a customer asking for a price and a delivery time for a described part or assembly.

Engineer-to-order

In engineer-to-order, a product is designed or worked out only after the customer has ordered.

Nesting

Nesting is arranging parts on a sheet or profile as tightly as possible, to reduce material waste.

Post-calculation

Post-calculation sets the hours and costs booked on a finished order next to what was planned for it.

Capacity planning

Capacity planning sets the work in the order book next to the available machine hours and people hours.

OEE (overall equipment effectiveness)

OEE sums up in one percentage how much of the available machine time actually produces good parts.