Important Tips on Metal Finishing

Surface finishing is an important part in the design of custom metal parts. It can help protect your part and make it more attractive. It can also help absorb light, reflect light and change your part’s friction. There are two categories of custom parts namely functional and decorative. Functional custom parts are those usually used inside devices. On the other hand, decorative custom parts consider appearance as important, and these are the ones that will usually require finishing. Below are important tips on decorative metal finishing.

Buff Polishing
It leaves a glossy finish on your parts’ surfaces, especially those that can be accessed by the polishing wheel. It can also work for rounded edges. A good metal finisher must be used for good results. Chrome plating or bright nickel plating can help achieve that bright and long lasting finish, and avoid having to brighten up your finish periodically.

Electroplating
It provides a number of metallic coloured finishes. The most common forms of electroplating are chrome, zinc, and nickel.

Anodizing
This form of metal finishing can provide a clear, black, or coloured finish. It is mostly applicable on aluminium metals.

Powder Coating
It leaves a durable colour layer, and is largely preferred to painting. For plastics, injection moulding achieves a much better finish than milling. Acrylic has been found as the best for polishing plastics.

Milling
Milling creates surfaces that may have complex patterns from cutting. Applying a mechanical finish will achieve the best appearance. For flat parts, you can use brushing, or powder coat finishing. Non-flat parts can attain a great appearance by polishing with a good metal finishing machine.

How to Compensate for Finish Thickness
When you add a surface finish to your metal part, you will realize that it changes the size of the part slightly, depending on the metal finisher you use. In some designs, you may need to put this into consideration when specifying the part’s dimension. It is worth noting that mechanical part dimensions can only apply after non-organic finishes such as mechanical finishing, electroplating and anodizing. For organic coating such as powder coating, it has to be done before.

It is important that you specify whether or not threaded holes on your part should be plugged to avoid finish. In critical cases, you should specify tolerance on your part’s finish thickness. With a good metal finishing machine, you should achieve that desired finish on your metal parts.