Guides and Articles
Metal Foundries: Cast Components, Patterns and Finishing Work
Understand metal casting, the roles of molds and patterns, and the differences between as-cast components, machining and fabricated assemblies.
Metal foundries produce castings by forming metal in molds. The mold defines the component's basic shape; later work may develop selected surfaces or features. Cast housings, brackets and other shaped components are different products from metal stock supplied as sheet, bar or tube.
Casting and Fabrication
Casting creates a shape from metal within a mold. Fabrication builds a product from existing material forms through supported forming and joining work. A cast housing and an assembly made from plate may serve related purposes, but they are different manufacturing approaches.
The distinction matters when discussing a replacement. A drawing, existing part and required material identity describe the component more clearly than asking for a similar-looking piece of metal. The manufacturing route needs professional review.
Patterns, Molds and Component Geometry
Patterns and molds help establish the casting's shape. Internal cavities and external surfaces create different production questions. The foundry needs to understand which features come from casting and which require subsequent work.
For example, a component's broad body may be cast while selected mating surfaces or holes are produced later. A quotation for an unfinished casting and one for a component ready for the next assembly stage therefore cover different outputs.
Machining and Secondary Work
CNC machining and production machining can develop supported features after casting. These services may be performed by the foundry or another business. The finished component should be described by the work completed, not simply called a casting without qualification.
Some foundries also undertake metal fabrication or welding as separate supported work. Those capabilities are not inherent in every casting operation.
Development and Repeat Production
A new component can require development before repeat orders. Prototype production helps examine a proposed product at an early stage. Repeat casting then involves its own production and inspection requirements.
A replacement for an existing part differs from a new design because existing geometry and records may provide a starting point. They do not remove the need to identify the material and finished features required.
Foundry Questions
Is an as-cast part a fully finished component?
Not necessarily. Machining or other finishing may remain.
Does every foundry cast every metal?
No. Material and product capabilities vary.
What should a component enquiry include?
Available drawings, material information, required finished features and quantity, while distinguishing development work from repeat production.