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Guidelines
for Casting Buyers
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It is important that the foundry and the casting purchaser establish a good relationship in order for the casting producer to make an acceptable cost effective part.
Specifications
Over specifying can increase the cost of a casting appreciable. For example the selection of an alloy that is more difficult to melt. The selection of an alloy that is susceptible to cracking during the solidification process, permission to weld repair, choosing the right chemistry and heat-treatment requirements and finally improper quality requirements adding substantially to the casting cost such as enforcement of radiographic standards in non critical applications.
Under specifying leads in many cases to miss-understanding between the casting producer and the casting supplier. Castings that are designed for critical applications require specific quality criteria. Selection of material that does not meet environmental or mechanical properties frequently leads to poor casting performance.
New Jobs
What are the requirements of first run or sample castings?
- Is written sample approval requested?
- Is 100% casting layout required?
- What inspection standards are required: x-ray or liquid particle inspection?
- Tolerances and dimensions must be clearly legible on the raw casting and machined casting drawings?
- What as received casting condition is specified? Is shot blasting, surface finish, packaging or shipping requirements specified?
- Price, delivery and production quantities should be clearly defined.
- Casting certification critical to casting performance must be agreed to in the quotation. Mechanical and physical test must be specified.
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