Learning about the pros and cons of aluminum vs. steel molds
In this article we will cover: The pros and cons of aluminum molds, The pros and cons of steel molds, and The pros and cons of aluminum vs. steel molds at Design-Tek.
The pros and cons of aluminum molds
As recently as ten years ago, many mold makers resisted using aluminum for molds. There was an unsupported claim in the molding world that aluminum couldn’t handle the heat and pressure that are an integral part in molding plastics, glass, and other materials. That myth continued to expand until many companies looking for molds would not have paid for aluminum molds, no matter how effective they may have been.
Thankfully for everyone, the rumors about aluminum have been proven largely false. Aluminum is not a perfect molding metal, but it is less expensive than steel and other metals. It is also lighter which makes molds easier to transport and handle during the molding process. Its light weight also means parts made in aluminum can be heated and cooled more quickly, providing much faster turnaround rates for products, sometimes as much as 50 percent faster. Aluminum also has uniform heat distribution which means plastic parts made in aluminum molds don’t shrink or distort as much as they do in other molds; for example, aluminum is seven times faster at heat dissipation than steel. And because there is less distortion, fewer materials are thrown away as scrap due to cracking, warping, or breaking.
Some manufacturers are still wary of aluminum’s durability in molds. The truth is aluminum molds can’t always make millions of parts from the same mold; though, they can still make hundreds of thousands of parts. The amount of parts a mold can make depends on how big the parts are and the process of molding being used. Aluminum molds are most effective for small parts, yet recently car manufacturers have begun using high strength aluminum for some of their larger car parts as well that have been shown to be as effective as those made from steel.
Because aluminum is so flexible, it can also be used for molds of very intricate parts with unusual designs. That being said, aluminum molds have to be carefully constructed and cleaned after use to prolong their use. If aluminum molds are not made and finished properly, gaps and errors can be accidently introduced to the parts causing them not to fit with other parts.
The pros and cons of steel molds
Steel has always been shown to be an effective metal for molds. It is a durable metal that can handle high heats and pressures without any change in the shape of the molds, and it can be used for millions of parts from the same mold. Steel molds hold up against the elements without rust and provide good finishes to each product.
Unlike aluminum molds, steel molds can be easily made and maintained. However, steel’s strengths are also its weaknesses. Steel molds do not heat and cool quickly—they cause longer production times and can often contribute to more shrinking and warping of the parts.
Still, steel molds can handle any size run of product without worry. Steel is a tried and true favorite in the molding business.
The pros and cons of aluminum vs. steel molds at Design-Tek
At Design-Tek Tool and Plastics in Utah, we offer many types of aluminum and steel molds. The pros and cons of both types of molds can sway us toward the better metal for whatever product you are looking to make. Here are a few of your options for aluminum and steel molds at Design-Tek.
QC7 mold aluminum: a high-impact aluminum that can handle large runs and products.
Pre-hardened 4140 mold steel: a steel that can be molded without a hardening stage. It can withstand your tough projects with its good tolerances.
Tool steels S7, A2, D2, stainless steel: these metals can keep optimum hardness after machining. They are used mostly for cores, slides, and other parts that need durable strength.
Aluminum copper: an aluminum hybrid that is often used for parts that need to be able to move inside the mold.
Our Design-Tek staff knows the pros and cons of aluminum vs. steel molds. We have the equipment to make both metals work for your products, including CNC Mills, a surface grinder, an EDM sinker, a sand blaster, and a polishing station.
Contact us for a free quote on aluminum or steel molds at 801-393-4400, or by email at info@designtekplastics.com.