In manufacturing, tooling is the process of producing the required components and machines for any given job. Manufacturing aids, or tools, including jigs, gauges, fixtures, molds, cutting tools, and specialized patterns that are of limited use on a specific production line or operation, must be produced in such as a way that they can operate consistently over the entire manufacturing run.
As such, employing the right kind of tooling is an extremely important consideration for manufacturers. If tools fail to operate in the correct manner, then the final products will be flawed. Therefore, having the proper tools in place directly impacts the output, product lifecycle, quality, reliability, and cost of a finished product.
It’s no surprise then that using the right tooling material is a primary consideration for a manufacturer. Any number of materials can be used, ranging from the commonly employed steel to a host of plastics and even more uncommon materials such as wood. But more and more manufacturers are finding that aluminum alloys bring a host of benefits that can’t be ignored.
Tooling made of aluminum alloys offers a wide array of advantages. Compared with harder metals such as steel, aluminum is generally much easier to cut and it cools much more quickly. This leads to reduced cycle times and cheaper costs. Of course, experience shows that aluminum is not the right choice for every application, as it depends on a number of factors, including the specific part being produced, the volumes involved, the temperatures that might need to be applied, and any ancillary operations that are being performed.
When it comes to volume, the traditional approach to aluminum has been to use it only for prototypes and low volumes. However, the development of a number of harder aluminum alloys that have been enhanced through advanced heat treatment has meant that aluminum tooling can now be used in far more applications. It is not uncommon for manufacturing runs to surpass more than a million components from an aluminum tool while still maintaining the same quality and consistency.
No matter what material you use, tools wear down and quality can degrade if the proper process isn’t used and the parts aren’t adequately monitored and maintained. This is true of both steel and aluminum. However, aluminum, because of its higher thermal conductivity, is able to diminish or overcome altogether many of the frequent issues that occur with molds in the manufacturing process. For instance, aluminum alloys have even heat distribution, eliminating any hot or cool spots on a tool. Aluminum also cools evenly, which helps avoid warping or shrinkage.
Just the simple fact that many of the aluminum alloys that are commonly used today were developed for the aerospace industry should put manufacturers at ease. These alloys needed to be highly consistent and reliable. Thanks to having been tested in such extreme conditions, alloys such as 7075 have been used by aircraft manufacturers for years to strengthen aircraft structures. Now, the thermal conductivity of these alloys can significantly lower cycle times and costs.
And while many people have assumed that aluminum is not strong or durable enough for their larger production runs, others shy away from aluminum because they worry about the expense. The truth is that using aluminum tooling for a prototype actually saves money. Aluminum, because of its versatility and affordability, makes it the perfect material when working out the kinks in the production process.
When it comes to picking out the right alloy, a number of factors must be taken into account. For instance, when working with injection molds, several grades of aluminum make sense. On the softer end, general purpose 2024 aluminum alloy is a smart choice. It can be used in applications that require a high strength to weight ratio, and it also offers good fatigue resistance.
Industries such as automotive are more and more frequently turning to 7000 series alloys, mentioned above. Timothy Logan, Vice President of Clinton Aluminum,
Innovative Alloys has explained, “There are numerous grades of aluminum, and selecting the correct grade of aluminum with the number of parts required and plastic requirements will result in a definite cost savings.” He has also pointed to an automotive manufacturer that performed a three-year study and recommended 7000 series aluminum as the strongest alloy. The study found that an aluminum injection mold made from a 7000 series aluminum alloy can surpass 2,000,000 units for a single tool. Another added benefit of the 7000 series is greater corrosion resistance.
One alloy in particular offered by Clinton Aluminum that is popular for tooling applications is Hokotol. Its characteristics include low weight (approximately three times lighter than steel), excellent machinability, high uniformity of mechanical properties across its total thickness, excellent mechanical properties in the center of the plate, high thermal conductivity, and excellent electrical conductivity. What sets Hokotol apart from other aluminum alloys is its superb dimensional stability. Also, with regards to its surface porosity, this alloy is suitable for the most demanding applications.
This is important because another critical consideration when it comes to choosing an alloy for tooling is porosity and inclusions. In general, aluminum alloys do a good job of proficiently machining, finishing, and accepting texture. Most premium aluminums can accept a polished surface. And although the softer and less expensive alloys can be prone to a greater level of impurities due to porosity, because extra finishing cost is seldom an issue and the focus is on the initial tool cost, aluminum is still an excellent choice for prototype tools.
Aluminum alloys are a durable, adaptable, and high quality option for your manufacturing needs. Tools made from aluminum make more financial sense because they offer the best combination of flexibility for creating quick and effective prototypes and strength for use in applications that offer a longer life cycle.
Clinton Aluminum adheres to a philosophy of “The Right Alloy for the Right Application” and we take pride in being a technical resource partner to our suppliers and customers.