To inspect castings properly, check four things in order: how they look, whether they are the right size, whether the metal is the right grade, and whether they are sound inside. Casting inspection in India works best when you agree the method and sample size in the purchase order, before the first pour.
Most foundries do some of this themselves. Your job is to decide which checks you need independent proof of, and to see them done on parts from your own lot.
1. Visual inspection
Start with the surface. Look for cracks, cold shuts, sand inclusions, surface porosity, rough fettling and any repair by welding or filling that was not agreed. Compare against an approved sample or a visual standard.
Visual checks are fast, so inspect every piece or a large sample. The common faults are listed in casting defects, and a retained approved sample helps settle disputes.
2. Dimensional inspection
Measure the critical dimensions on a sample, using gauges, callipers or a coordinate measuring machine. Mark critical dimensions on the drawing so the inspector knows where to look. Agree the tolerance class in advance, typically under ISO 8062.
How many pieces to measure depends on the lot size and the risk. Dimensional inspection and sample size explains the usual approach.
3. Chemistry and mechanical properties
The foundry takes a spectrometer reading from each melt and casts test bars for tensile and hardness tests. Ask for the results as a material certificate, usually EN 10204 3.1, and check that the heat or melt number is traceable to your parts. See the EN 10204 3.1 material test certificate.
For a high-value order, have an independent laboratory test a sample cut from a casting from your lot, not only a separately cast test bar. The two can differ.
4. Non-destructive testing
Surface faults and internal defects are found with different methods. Dye penetrant and magnetic particle testing find surface and near-surface cracks. Ultrasonic and radiographic testing look for internal shrinkage and porosity. Apply them where the part is pressure-bearing, safety-critical or the drawing requires it.
These tests cost time and money, so specify them for the right parts and extent. Read radiography and ultrasonic testing for castings before deciding.
Who should carry out the inspection?
The foundry's own quality team handles the in-process checks. For final inspection, choose between your own representative, a sourcing agent working for you, or a third-party inspection company. A neutral inspector matters most when you cannot attend, or when the contract needs an independent certificate. See third-party inspectors in Gujarat.
Whoever inspects, write down the accept and reject criteria and the sample size, and keep the report with the batch number.
Also decide what happens to a rejected lot before the order is placed. Agree whether the foundry sorts, repairs or remakes the parts, who pays for re-inspection, and how long the fix may take. Repairs by welding or impregnation should need your written approval, because they can hide a defect that returns in service.
Next step
We audit foundries, check samples and certificates, have lots tested and supervise loading, for a single fee agreed in advance. Book a free sourcing review to set up an inspection plan for your castings.