What are the common processes for mass production of metal parts?

For metal parts, the cost of parts will always be higher than that of plastic parts. Depending on the process used, it can be slightly higher or much higher.

The following are common processes for producing metal parts:

Sheet metal: Origami works very well-sheet metal molds are manufactured quickly and cheaply, and the delivery time is short. Sheet metal can replace injection-molded plastics for internal structural parts, because in the early stages of the design process, when the product may still be changed or the product's prediction is unclear, it can provide greater flexibility.

CNC machining: When the shape of the part is very complicated, CNC machining may be required. For relatively small parts, this is very expensive, and the return on investment (ROI) of the die casting process is usually within a few hundred parts.

Turning: This is usually the only method for shafts and bearing surfaces. There are some professional metal parts processing suppliers that only focus on customized turning shafts-if you have precision bearing surfaces in complex mechanical parts, this is the price you need to pay.

Sand casting: used to produce a small number of customized metal parts with complex geometric shapes. Without tools, sand is used as the tool material, and the sand mold is formed around the positive model of the part (usually the CNC version of the metal part). Remove the positive electrode, put the two halves of the sand mold together, and pour the molten metal to shape the parts in the voids inside the mold. When the metal solidifies, the sand mold will break and the parts can be taken out. This process produces a rough surface finish and does not retain fine features. Sometimes post-processing processes are performed to create the required tolerances for critical surfaces.

Investment casting: It is used for castings with complex geometries, one step higher than sand casting. The front model or pattern of the part is made using a wax-like substance. Then an "investment process" is carried out to form a coating around the wax-forming mold. The wax is then burned off, and the metal is poured into the resulting mold cavity to take the shape of the wax. This process also cannot maintain tight tolerances, so post-processing is required to strengthen the tolerances on critical surfaces.

Die casting: This process will produce higher mold costs (usually 5 digits per mold) and longer delivery time (usually 5 months, while injection molding is 3 months), but the cost of parts is low. A hardened tool steel mold is created to form a mold very similar to the mold used in injection molding, and then molten metal is poured into the mold to form the part. Post-processing also requires tightening the surface with tight tolerances.

There are other technologies such as EDM (used to burn complex shapes into metal blanks before processing is complete, usually used to make complex molds), wire-cut EDM, and water spray (used to create complex shapes for effectively flat parts )Wait.

For some types of metals, secondary processing is sometimes involved. For example, aluminum parts are often treated with hard anodizing to form an impermeable coating that protects the parts from oxidation. Spring steel parts are sometimes heat treated to improve their material properties.