Forming and Shaping Techniques

Forming Techniques for Metals

Casting: A technique in which liquid metal is poured into a mould. Upon cooling and solidification, it takes the shape of the mould, forming components such as cylinder heads and crankshafts.
Forging: Involves heating metal till it’s malleable, then shaping it by striking or pressing. Forging increases metals’ toughness and decreases brittleness.
Extrusion: Hot or cold metal is pushed through a shaped ‘die’ to form long pieces with a uniform cross-section. Aluminium window frames are an example.
Bending: This process allows a flat sheet of metal to be transformed into a variety of shapes. It can be done with simple tools like ‘folding bars’, or complex machines such as ‘press brakes’.
Spinning: A metal disc is rotated rapidly and formed over a wooden or metal former using hand tools. Commonly used to create symmetrical, circular items like lampshades.

Machining: Removing material from a metal workpiece to get the desired shape. Different methods include milling, turning, drilling, and grinding.
Pressing: This process uses a ‘die’ and ‘punch’ to shape metal. It’s often used to mass-produce components with great accuracy and finish.
Sintering: Powdered metal is heated to just below its melting point, causing the particles to bind together and form a solid piece. Sintering is commonly used in manufacturing precision parts.
Electroforming: Uses electrolysis to shape and harden the surface of items. Ideal for producing complex structures with high precision.

Sanding and Polishing: Performed to smooth out the surface of metal and to increase its aesthetic appeal.
Painting and Coating: Applied to protect metal surface from rusting and corrosion, as well as to enhance its appearance.
Anodising: It’s especially common with aluminium. Anodic films can be used for a number of cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add interference effects to reflected light.