A number of designers, engineers and purchasing decision-makers still labor under several misconceptions about the use of die casting; the most prevalent being that die casting — specifically tooling — requires long lead times and is only suitable for high-volume production.
The development of modern rapid tooling techniques should put an end to that misconception, and help designers bring the benefits of die casting to a much greater range of applications.
Today's rapid tooling methods can reduce lead time to as little as seven days in some cases, and be cost-effective for production volumes as low as 1,000 parts. At the other end of the spectrum, there are methods to quickly produce high-volume durable dies suitable for running up to 100,000 parts and even more in some circumstances.
For example, there are 12 different tooling production methods for low-volume work (1,000 parts or less) with lead times from 19 weeks to as low as one week! (Learn more about these methods at http://www.diecasting.org/research/rapidtool/).
One example of the benefits of rapid tooling is a collaborative effort by St. Clair Die Casting, NADCA and Case Western Reserve University that improved production for a cast aluminum heat sink used in military tank treads. The rapid tooling process cut tooling time from 26 weeks to four weeks, and also resulted in significant improvements in die life.
Tank tread usage is five to 10 times as high now as in peacetime conditions, according to estimates by the Army's chief logistician, but tooling is often not available to produce spare parts for aging weapons' systems. As demand for the heat sinks began to increase in 2004, St. Clair Die Casting, based in St. Clair, MO, needed to reduce the lead times for the heat sinks to improve weapons' systems readiness.
The previous technology, which required a tooling lead time of 26 weeks, was a three-step process that involved machining the inserts from annealed material, heat treating the die steel, and finally, machining the tool to the final size. The new process cut tooling time by eliminating the heat treating and final machining. Using the simplified process, the tooling materials were pre-heat treated to a 40-42HRC specification, then machined to final size.
Improving existing production processes is just one way to use rapid tooling. Test marketing is another valuable application. One die caster created 500 housings for high-intensity discharge headlights to test the application on tractors and construction equipment. The manufacturer noted that more farmers and road crews were working at night, so the brighter lights would be a benefit. However, previous plastic housings melted because of the extra heat generated by the high-intensity lights.
Creating actual parts using a die casting allowed the manufacturer to test the product under real working conditions, while accumulating data on the benefits of this product improvement to assist with marketing the new lights to a wider range of users. In this case, rapid tooling may not only open new markets for the OEM, but also provide more business for die casters by using a die cast part to replace a plastic part.
These are just two examples of how die casters are using rapid tooling to dispel myths about die casting. By improving production and helping manufacturers introduce new products, North American die casters are leading the way with innovative technologies to better serve their customers.