6 Metal Finishing Techniques for Adding Value

Aug. 17, 2023
Machine shops and other manufacturers are doing more with the parts they produce, in order to provide more to their customers and get more in return.

All manufacturers know they need to add “value” to their output, to satisfy and hold on to their customers, and to attract new ones. For machine shops and fabricators, “added value” frequently comes by instituting manufacturing services. Metal finishing describes the various processing steps that provide the manufactured parts with various desirable properties. For example, metal finishing may improve parts’ durability and aesthetic qualities, increase chemical and electrical resistance, or prevent tarnishing. Manufacturers are doing more in order to provide more, and get more in return.

Here are some finishing options that are well worth considering:

1. Powder coating. Manufacturers continually look for ways to improve metal-finishing techniques that they’re performing already. In one case, researchers received a patent for a new coating that could replace the hazardous heavy metals used for finishing.

Well-chosen coatings can make metal more functional – and powder coating is an excellent example. This is a well-established finishing option for products that may be intended for use in the open air and exposed to sun, rain, and other outdoor uses – e.g., lawn furniture.

However, powder coating has many other applications that you may not expect. Consider the artistic decisions made while revamping a former metal foundry at the University of Delaware that’s now a multipurpose space. Designers used coiled-wire fabric for the walls and ceilings. Then, they powder-coated the material for a satin-copper finish. It’s an aesthetic turn for the practical finishing step.

2. Electropolishing. Some metal-finishing techniques are associated with particular base materials. That is the case with electropolishing, which manufacturers frequently apply to stainless steel or other alloys. This finishing option involves removing a thin layer of the substrate metal to make the resultant surface smooth and shiny.

The electropolishing process typically involves using specific chemicals. For example, electropolishing stainless steel requires a high-viscosity mix of sulfuric and phosphoric acid. However, research is underway to discover other electropolishing options that may work as well or better.

Consider a European Union-funded project for the first dry electropolishing technique. It grinds and polishes metals with a biocompatible method that adds corrosion resistance and gives a mirror-like finish.

3. Anodizing. Consumer expectations and regulatory requirements have pushed manufacturers toward sustainability – making them more aware of the resources they are consuming in their production programs. Often they will look for "greener" alternatives to materials and resources . Anodizing is a good example of eco-friendly metal finishing, categorized that way because it does not produce greenhouse gases.

This process makes metal corrosion-resistant and mechanically stronger, increasing the components’ service life. Anodizing also will not interfere with the materials’ recyclability, and anodized metal needs no additional processing before entering the recycling stream.

Anodizing creates a coating from the base metal, and manufacturers may use additives to achieve other characteristics, notably colored finishes. However, anodization is a water-based process that does not generate volatile organic compounds (VOCs).

4. Blasting. Blasting uses sand, metal, and/or other media that are propelled at the parts’ surface at high speeds. It’s widely used to clean parts’ surfaces, and it’s an effective method for creating a uniformly matte texture, particularly in soft metals.

A variation called shot peening is a blasting technique that makes metals more resistant to fatigue and stress-related cracking. It creates compressive stress to counteract the tensile stress that occurs during manufacturing.

Blasting is an effective preparation technique if manufacturers want to repurpose old pieces of dirty or previously coated metal. It removes paint and other coatings and it’s widely used for rust removal.

5. Automated metal finishing. Many manufacturers are eager to adopt new technologies that allow them to finish jobs faster and with fewer errors. That’s why many have explored how automation might create better outcomes for metal-finishing tasks.

For example, automated spray-coating machines reduce waste and improve accuracy when finishing metal. Those characteristics also help machine shops and fabricators get uniform results, even when dealing with oddly shaped parts or hard-to-reach areas.

Some metal fabricators also have automated flat-part finishing machines in their shops. They use conveyor belts that move components to various stations for different types of finishing. However, facilities can be even more advanced than that. One shop uses a cobot to load parts onto the conveyor. This approach frees workers for more demanding and/or rewarding tasks that use their skills, knowledge, decision-making, and other resources more appropriately.

6. Digital process management. Besides choosing the appropriate metal-finishing techniques, manufacturers must have streamlined processes that help them oversee workloads and spot bottlenecks. Some metal-finishing shops have as many as 40 minutes of dead time per job. The non-value-added tasks disrupt productivity and reduce a shop’s performance potential.

However, specialized software supports metal-finishing techniques by scheduling the resources needed to complete jobs. They help managers track specific details like products used or the number of people needed to finish a customer’s workload.

Such software often works in the cloud, allowing authorized users to access the content from anywhere. Then, people have the data necessary to reduce negative-profit-margin jobs and focus on the work that’s most likely to help the bottom line. They also can track which metal-finishing options are most popular with clients – which may inform areas of focus for the shop.

Which techniques will you try?

You may need to adopt more than one metal-finishing technique to get the performance results that you or your customer require. Knowing the effects that may follow from each method makes it easier to select the right finishing process and get satisfactory results.

Plus, digital process management and automation could significantly improve productivity, regardless of the specific finishing method you choose. Those possibilities are two examples of how manufacturers can use technology to improve performance and maintain quality control – delivering and gaining added value from their operations.

Emily Newton is the Editor-in-Chief of Revolutionized, an online magazine exploring the latest industrial innovations.