The Design Engineer’s Role in Casting Procurment

It is a well-known axiom that 70% – 90% of the cost of a product is the result of design decisions.  Although we might debate as to the preciseness of this estimation the fact remains that design is key element to the manufacturability, availability, reliability and overall affordability of any manufactured product.

Castings are inherently a cost effective method to manufacture shapes that reduces the part-count of an assembly and therefore improves the affordability of that product.  However, casting design does require some specialized expertise and appreciation of the strength and weaknesses of the foundry process.

Any poorly designed product as a consequence will incur unnecessary or unexpected costs.  For example, the cost of poor product manufacturability might be reflected in late deliveries, short shipments or frequent rejections.  These types of design related issues will drive a rise of both Inventory and Administrative costs.

Less obvious is the cost of a missed opportunity where the product might have been manufactured via a superior method.  Poor design choices can threaten both the reputation and profitability of an enterprise.

Good casting design accomplishes two things.  First the combining multiple parts into a one-piece cast structure will reduce the amount of assembly required to manufacture a product.  Such Part-Count Reduction favorably impacts not only the direct manufacturing cost but also reduces inventory and administrative costs.  Secondly, because of the Near-Net-Shape capability, castings reduce the cost for secondary machining.  Investment Casting is an effective foundry process by which to take advantage of both capabilities.

The Designing of Investment Castings is a relatively straightforward process as there are few constraints on configuration and it requires no consideration of a draft angle.  Therefore, anytime two separate members need be assembled together presents an opportunity to combine them into a 1-piece cast structure.  Obvious candidates for conversion to casting are dip-brazed or welded assemblies.

Admittedly there are a few casting design “Rules of Thumb” that do need to be taken into consideration and knowledge of those aspects will help to avoid any unintended “Designed–In” costs.  O’Fallon Casting readily assists its customers with several services to help enhance the value of their casting designs.  First O’Fallon Casting provides its customers a Concurrent Engineering Service to critique their casting designs and offer recommendations for improvement.  Secondly, OFC offers to conduct a 3-Hour, IC-101, class on the basics of Investment Casting design at Customer facilities.  Thirdly, O’Fallon Casting also offers a 3-Day, IC-201, class held at O’Fallon Casting for customers desiring an in-depth exposure to Investment Casting.

Castings provide an opportunity to enhance the affordability of customer designed products.  O’Fallon Casting wants to assist its customers in making the most effective use of castings in their products.

For more information please call your OFC Sales Engineer.