Ask what a metal casting foundry does and the honest answer is narrower than most buyers expect. It makes moulds, melts metal, pours, cools, shakes out, cleans, and inspects. What comes off the end of that line is a raw casting: the right shape, the right material, and not yet a usable part. Understanding where the foundry's job stops is the key to understanding where your supply chain problems start.
What the foundry does
Pattern and core making, or maintaining the tooling you supply. Sand preparation and moulding. Melting to a specified chemistry and, for ductile iron, treating the metal. Pouring, cooling, shakeout. Cutting off gates and risers, grinding, and blasting. Heat treatment where the grade calls for it. Inspection against the print and the material spec. Some foundries add basic machining; most do not, and the ones that do rarely treat it as their main business.
What the foundry does not do
- Precision machining of critical features — bores, faces, threads — to your tolerance.
- Painting, powder coating, plating, or other protective finishes.
- Metal fabrication: welding a casting into a larger weldment.
- Sub-assembly: bearings, bushings, seals, and hardware installed and tested.
- Freight, customs, and consolidation, especially from an international source.
- Inventory: producing to your forecast and holding stock so releases ship in days rather than months.
Each of those is a separate vendor with its own PO, its own lead time, its own quality system, and its own version of events when something is out of spec. A buyer who sources a raw casting has bought one part of a six-part problem.
Where the handoffs fail
A void discovered at the machine shop is the foundry's defect and the machine shop's schedule. Paint that will not adhere is the finisher's process or the foundry's surface, depending on whom you ask. A container that clears customs late belongs to nobody. Every handoff is a place where responsibility can be handed off with it.
The alternative
GW spent decades as a foundry and knows exactly where the foundry's job ends. Today we place the casting with the right foundry in a qualified domestic and international network, and manage everything after it: machining and finishing, fabrication, painting, sub-assembly, supply chain, and domestic inventory programs. Parts arrive finished and ready to use, on one PO and one invoice, from one company that stands behind the whole part.