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Face milling
A milling operation that machines a broad flat surface with the cutter face.
Rapid Prototyping Glossary
F
Definitions for commercial rapid prototyping, production, machining, casting, moulding, finishing and inspection terms.
Facing
A turning or milling operation that machines a flat face to establish length, squareness or a datum surface.
Family mould
A mould that produces two or more different part geometries in one shot, usually for parts used together in an assembly. Family tooling can be efficient but requires careful runner balancing and shrinkage management.
Family tool
A mould that contains cavities for different but related components in one tool.
Fan gate
A gate that widens like a fan to reduce shear and improve flow into broad thin sections.
Fatigue testing
Testing used to understand how a part behaves under repeated cyclic loading.
FDM
Fused deposition modelling; the common commercial term for filament-based material extrusion in which thermoplastic is melted and deposited through a nozzle.
FEA
Finite element analysis; a numerical method for predicting stress, stiffness, thermal behaviour and other responses.
Feature recognition
Software interpretation of CAD geometry to identify machinable features such as holes, pockets or bosses.
Feed
The rate at which the tool advances relative to the workpiece during cutting.
Feed per tooth
Also written fz; the distance advanced by a milling cutter for each tooth engagement, used in feeds-and-speeds calculations.
Feed rate
The speed at which a cutting tool advances relative to the workpiece.
FFF
Fused filament fabrication; the generic term for filament-based material extrusion, often used interchangeably with FDM.
Fibre laser
A laser source widely used in metal additive manufacturing, marking and cutting.
Fibre-filled composite
A material strengthened with chopped or continuous fibres.
Filament
Thermoplastic feedstock supplied as a strand for FDM/FFF printing.
Filament winding
A composite process that winds resin-impregnated fibres around a mandrel to create hollow structures.
Fill time
The time taken for molten polymer to fill the mould cavity from the start of injection to volumetric fill. Fill time strongly affects shear, venting behaviour and surface quality.
Fillet
A rounded internal or external corner used to reduce stress concentration or improve manufacturability.
Final machining
A finishing cut performed after roughing, heat treatment or semi-finish operations to achieve final dimensions.
Finite element analysis
The full term for FEA.
First article inspection
FAI; a detailed dimensional and documentation review of an initial part against the drawing and specification.
Fixture
A device that locates, supports or restrains a part during manufacture, assembly or inspection.
Fixture plate
A standard plate used to mount workholding elements, vices or dedicated fixtures.
Flame polishing
Using controlled heat to clarify and smooth the edges of some plastics, notably acrylic.
Flash
Excess material that escapes at a mould parting line or split line.
Flatness
A GD&T control that limits how much a surface may deviate from a perfectly flat plane.
Flexible resin
A photopolymer resin formulated to provide rubber-like flexibility or elasticity in SLA, DLP and related processes.
Flexural modulus
A measure of stiffness under bending load.
Flood coolant
A coolant delivery method that continuously floods the cutting zone with fluid for cooling, lubrication and chip evacuation.
Flow front
The advancing leading edge of molten polymer as it moves through runners and cavities. Flow-front behaviour influences weld lines, air traps and final packing performance.
Flow hesitation
A filling behaviour in which melt slows in one region while moving quickly in another, often because of wall-thickness changes or geometry transitions. It can contribute to weld lines, air entrapment or short shots.
Flow lines
Visible streaks or patterns on a moulded surface caused by resin flow behaviour.
Flow simulation
Digital analysis used to predict polymer flow, weld lines, air traps, pressure and shrinkage.
Foam core insert
An insert used within a moulded or reaction-moulded part to create a lightweight cored structure with reduced mass.
Foam injection moulding
An injection-moulding process in which a blowing agent creates a foamed internal structure, reducing weight and often helping with sink or thick-section control.
Foaming
The creation of a cellular internal structure in a polymer, sometimes used to reduce weight.
Form tool
A specially shaped cutter used to create a defined profile in a single pass.
Form-fit-function
FFF in product-development language; prototype fidelity that matches geometry, assembly interface and working behaviour.
Freeze-off
The point at which a gate or thin flow section solidifies enough to stop further packing flow. Gate freeze-off is critical when setting hold time and part consistency.
Functional prototype
A prototype built primarily to validate mechanical or operational performance.
Fused deposition modelling
FDM; a material-extrusion process that lays down molten thermoplastic filament in roads or beads.
Fused filament fabrication
FFF; the generic term for filament-based material extrusion, often used interchangeably with FDM.
Fusing agent
In Multi Jet Fusion, the jetted agent applied where powder should fuse under heat to form the part geometry.