Pressure Die Casting is a common technique for producing metal parts and components for various applications. Depending on the application, different die casting techniques may be used. In some cases, such as in automotive and aerospace, the use of a specific type of die casting process is mandatory, while in other cases, such as in general manufacturing and prototyping, different die cast techniques may be used.
One of the most commonly used types of die casting processes is the use of a drawbar system. A drawbar system consists of a flat sheet of metal, typically aluminum or magnesium, that is secured to a die casting die. To ensure pressure is applied evenly in the die cast, a drawbar is used to pull the sheet of metal down onto the die. As the sheet is pulled down, it forms a core, which will expand in volume under pressure. In this way, pressure is applied by the drawbar to introduce the molten metal into the core and form the part.
Drawbars come in various sizes, each of which is identified by a letter. The most commonly used drawbars are the A, B, and E sizes. The A size drawbar is usually the smallest and is primarily used in lightweight applications, such as those found in prototyping. The B and E sizes of drawbars are used in die castings with higher pressures, such as those found in heavy-duty applications or in the production of complex shapes.
When choosing a drawbar size, it is important to consider factors such as the pressure of the die cast, the type of die cast material being used, and the complexity of the part being produced. For example, the A size drawbar is designed to withstand pressures up to 20 tons, while the B and E sizes are designed for pressures up to 30 and 40 tons respectively. If a part is being produced that requires a significant amount of pressure, a larger drawbar size will typically be chosen. The higher pressure draws may also require additional components, such as draw pins, to ensure proper pressure is applied.
When choosing a drawbar size, it is important to remember that the pressure that can be applied to the diecast is limited to the drawbar size. Depending on the application, it may be necessary to use a slightly larger or smaller drawbar size to ensure that the pressure that is being applied is suitable for the material being used in the diecast. Additionally, when selecting a drawbar size, it is important to take into consideration the type of material being used and the complexity of the part that needs to be cast. By doing so, one can be sure that the desired drawbar size will provide optimal performance and produce the desired result.
