Rapid Prototyping Glossary B | Attwood Product Development

B-axis

The rotary axis that rotates about the machine Y-axis, commonly used on trunnion or swivelling-head multi-axis machines.

Back pressure

The resistance applied to the screw during plasticising in an injection moulding machine; used to improve melt mixing, colour dispersion and shot consistency, but excessive back pressure can increase shear heating and cycle time.

Back-draft

Reverse draft that locks a part into a mould or creates an undercut requiring slides, lifters or flexible tooling.

Backlash

Lost motion in a mechanical drive system, relevant to CNC accuracy and repeatability.

Ball end mill

A milling cutter with a rounded tip, often used for freeform surfaces, fillets and mould tool finishing.

Ball screw

A precision screw-and-nut drive using recirculating balls to convert rotary motion into linear motion with low friction and high positional accuracy.

Band sawing

A cutting process using a continuous toothed blade to section stock before machining or fabrication.

Bar feeder

An automatic device that feeds bar stock into a CNC lathe or turning centre for continuous or lights-out production.

Bar puller

A lathe attachment used to pull fresh bar stock forward from the spindle for the next operation cycle.

Barrel

The heated injection unit component in which polymer pellets are melted and conveyed towards the mould.

Barrel temperature

The controlled temperature profile along the injection barrel; also called barrel zone temperature. It must suit the resin and process window so the polymer melts consistently without degradation.

Baseplate

The rigid plate or platform used to mount a workpiece, fixture or additive build.

Batch production

Manufacturing a defined quantity of parts together rather than continuously; common in prototyping, pilot builds and low-volume work.

Bead blasting

A finishing process that uses glass or ceramic beads to create a uniform satin texture and remove minor marks.

Bearing surface

A surface designed to support load or provide controlled contact, often requiring tighter tolerances and smoother finish.

Bed

The main structural base of a machine tool that supports the guideways, table or saddle and contributes to stiffness and vibration control.

Bevel

A flat angled edge, commonly used as an alternative term for chamfer.

Binder jetting

An additive process that selectively deposits binder into a powder bed to form a green part, usually followed by curing, depowdering and often sintering or infiltration.

Black oxide

A conversion coating used mainly on steel to provide mild corrosion resistance, reduced glare and a dark cosmetic appearance.

Blanking

A sheet-processing operation in which a flat part profile is cut from sheet stock, often by punch or die.

Blast cabinet

An enclosed machine used for bead blasting, grit blasting or vapour blasting operations.

Blind hole

A hole that does not pass fully through a part and therefore has a defined depth.

Blow hole

A gas-related void or surface defect found in cast or moulded components.

Blow moulding

A process for making hollow plastic parts by inflating a hot parison or preform against the walls of a mould.

Blowing agent

A physical or chemical additive that releases gas during processing to create a cellular or foamed internal structure, as used in foam injection moulding.

Blush

A cosmetic discolouration near a gate or high-shear region, usually seen in injection-moulded parts.

Bond line

The interface between two joined materials, such as an adhesive joint or welded seam.

Bore

An internal cylindrical feature produced by drilling, boring, reaming or moulding.

Boring

A machining operation that enlarges and trues an existing hole to improve diameter accuracy, roundness or concentricity.

Boss

A raised cylindrical feature used to receive screws, inserts, spacers or mating parts.

Box build

The assembly stage in which fabricated or prototyped subcomponents are integrated into a finished enclosure or product.

Break edge

A note instructing that a sharp edge should be lightly removed by chamfering or deburring rather than left knife-sharp.

Breakaway support

Temporary support material designed to be manually removed after additive manufacture.

Bridge mill

A large milling machine architecture in which the spindle head travels on a bridge spanning the table, often used for sizable components.

Bridge tool

A temporary mould used to supply parts before a long-life production tool is available; also called bridge tooling.

Bridge tooling

Interim tooling used to bridge the gap between prototype development and full production tooling.

Broach

A multi-tooth cutting tool with progressively larger teeth used to form keyways, splines, square holes and other internal or external profiles.

Broaching

A machining process that uses a broach in a push or pull stroke to cut complex profiles in a single pass.

Build chamber

The enclosed process space of an additive machine where temperature, atmosphere and the layer-building environment are controlled.

Build envelope

The maximum part size or usable working volume of a machine.

Build failure

An additive manufacturing build that does not complete successfully owing to warping, recoater collision, detachment, poor fusion or machine error.

Build orientation

The direction in which a part is positioned for additive manufacture, affecting support, strength, surface finish and build time.

Build plate

The platform on which an additive build starts and to which the part or supports are attached.

Build preparation

The pre-print stage of orienting, nesting, supporting and slicing a digital model for additive manufacture.

Build rate

The speed at which material is deposited or fused, often expressed volumetrically or by layer time.

Bumpoff

A flexible moulding feature that allows a minor undercut to release by elastic deformation during ejection.

Burn marks

Darkened or scorched areas on a moulded part caused by trapped air, excessive shear or local overheating; sometimes called gas burns. Proper venting, lower fill speed in critical zones and balanced processing help to prevent them.

Burnishing

A finishing method that smooths and work-hardens a surface by plastic deformation rather than material removal.

Burr

A small unwanted raised edge left by machining, cutting or trimming.

Bushing

A sleeve or guide element used for wear surfaces, alignment or drill guidance.