Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould. Injection moulding can be performed with a host of materials mainly including metals (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers.

Injection moulding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection moulding, which vary greatly in their size, complexity, and application. The injection moulding process requires the use of an injection moulding machine, raw plastic material, and a mold. The plastic is melted in the injection moulding machine and then injected into the mold, where it cools and solidifies into the final part. Tools can be used to manufacture one consistent part in a repeating process or incorporate multi cavities (a multi impression tool), that is many components can be manufactured on the same tool repeatedly with a single injection.