Sand casting is the metal-forming process of first creating a mold from a three-dimensional pattern of sand. Molten metal is then poured into the mold cavity for solidification, after which the sand mold is removed. But, there are several variations that may make the process take longer. A completely new design, for example, might take longer to prototype and test. Cores may need to be created to use in the mold to form internal structures or walls. In addition, a secondary machining process may be required after casting to improve product accuracy.

Typical products made through sand casting include engine blocks, cylinder heads, cylinder pistons, frames, brackets, manifolds for high-horsepower engines, impellers, housings, gearbox parts of transmission systems for construction, and agriculture equipment. This article looks at some of the typical sand casting lead times.

What Factors Affect Lead Time in Sand Casting?

Lead time in sand casting refers to the amount of time between order placement and casting delivery. In general, sand casting has a relatively fast turnaround time, usually in the area of 3-5 weeks. Some customers might be very flexible in their schedules, while others may have very tight delivery timeframes, as the component they need may be part of a larger assembly that has its own delivery demands. Factors that affect lead time include:

• Foundry Capabilities: Part of lead time is dictated by the foundry’s own schedule and capabilities. Certain times of year may be busier than others, as demand levels can fluctuate. During high-demand periods, a small foundry with limited capabilities might have a more difficult time delivering the final product than a larger facility with multi-functional capabilities and state-of-the-art technology. Smaller foundries might not have hot-box and cold-box core-making capabilities, may have limited access to resin-sand and green sand, and might not have the ability to pour different metals.
• Design and Prototype Times: Depending on foundry capability, an existing product or design can usually go into production quite quickly. Delays can occur, however, when a part is brand new or very complex. This might require additional time for design, prototyping, validation, and testing. If a part is new, the prototype can require several levels of modification to make it suitable for the application at hand. Impro will discuss your project and possible techniques that could cut down on the lead time so you obtain your component in the shortest time possible.
• Component Complexity: An intricate component might take a longer time to design and test, or to produce the necessary sand molds. Higher levels of quality control, very tight tolerances, or additional testing measures may slow the production process.
• Finishing Needs: A combination of precision machining processes and heat treatments or surface treatments may be required to produce accurate components with high tolerances and excellent surface quality. Precision machining often requires the programming of computer numerical controls, or CNC, which allows for converting special designs into exact shapes through multiple dimensions.
• Foundry Capabilities: Some casting facilities have all the design, engineering, production, and testing facilities needed in-house. They are able to assist in drawings and simulations and can conduct applicable testing.
• Open Communication: Open communication between customers and the foundry is helpful to speed the production process. Provide as much information in advance as possible regarding volume, complexities, materials, and testing requirements, to spell out exact requirements and limit delays due to misunderstandings. Appoint someone at your facility to serve as liaison, who is responsible for quickly obtaining information and communicating customer needs.

3D Printing – A Time-Saving Advance in Sand Casting

Impro is extremely experienced at developing complex sand castings using 3D printing technology, which can dramatically decrease product development and lead time. This process may take anywhere from 30 minutes to 7 days to produce a customer’s part, depending on the part’s size, as well as its complexity. Once the design is finalized, sand mold and sand core(s) can be directly printed and used for part production.

Learn More About Sand Casting

Impro is a global, integrated manufacturer of high-precision, high-complexity and mission-critical components for diversified markets. We use state-of-the-art process technologies and equipment. If you are interested in finding more information about sand casting and our process capabilities, please contact our team of experts today.