Choosing the right metal finish isn’t just a matter of color. It’s a complex and intricate process that affects the functionality and even lifespan of the metal.
Think about the Golden Gate Bridge, completed in 1937, the bridge’s finish has stood up to the salt-laden fog of the San Francisco Bay for 80 years. While the “International Orange” paint has become the bridge’s trademark, it’s not there for aesthetics. The finish is there to protect the bridge from corroding as a result of the salt in the air from the Bay. The original lead paint was replaced with an inorganic zinc silicate primer and vinyl topcoat to protect against advanced corrosion.
In producing sliding hardware that sees a variety of different applications and environments, we need to protect our slides from the elements just like that of the Golden Gate Bridge. That’s why we have incorporated slide finishes to accommodate the needs of every environment our slides will see.
What is a Slide Finish?
A finish is a protective, chemical layer that helps a metallic surface resist corrosion. Aside from the stainless variety, steel is vulnerable to even light moisture. Thus, proper finishes can extend a drawer slide’s life by years.
Just what goes into a slide finish? Let’s find out.
The Types of Finish
Accuride offers four types of coated finishes for its carbon steel slide members:
- White Electrocoat Weather-Resistant
Zinc is the most common of the three finishes: It uses a zinc base layer coated by clear or black chromate. The clear zinc coat, the standard finish, resists a moderate degree of corrosion. It’s best for indoor environments, like office and home cabinetry.
Black electroplate, often used, by comparison, offers eight times more corrosion-resistance as clear zinc and tends to be used on dark-colored cabinetry. White electrocoat offers, even more, corrosion resistance on kitchen fixtures and appliances—applications that are often white, to begin with. These colors help the slides blend into the applications they’re used on. Our weather-resistant slides use a standard zinc finish with extra coating to protect the slide from the elements in outdoor applications.
You may be wondering where the “electro” come in. The electro part is from the role that positive and negative attraction plays when bonding the desired finish to the slide member. That powerful attraction gives the finish and slide surface a strong bond that leading to a tidy and resilient finish.
Additionally, there are corrosion-resistant aluminum and stainless steel slides, such as our ‘AL‘ and ‘SS‘ drawer slide families. These types of slides offer the most resistance to corrosion. The ‘AL‘ slide family consists of a slide with Aluminum raceways such as our, super heavy-duty AL4120 that boasts a load rating of up to 1,212 lbs.
From our stainless steel selection, slide SS0330 is ideal for applications subject to moisture or humidity such as refrigerators and freezers. In general, stainless steel includes anywhere from 10% to 30% chromium for anticorrosion. Accuride stainless steel slides are either austenitic or ferritic.
Austenitic steel is non-magnetic, highly formable, and has high corrosion resistance. Highly formable, austenitic steel is tough, optimal for welding, and used for such applications as auto trim and industrial hardware.
Ferritic steel is composed of up to 27% chromium (and 0% nickel), and it’s considerably less corrosion-resistant than austenitic steel.
Each finish is tested in a salt spray (also known as a salt fog) chamber. As the name suggests, these chambers have slides exposed to salt spray. The more corrosion resistant a slide’s coating, the longer its exposure in the chamber.
A basic clear zinc-plated slide is exposed for 12 hours in the chamber with no sign of corrosion. By comparison, an electro-white slide is exposed for 500 hours with no sign of corrosion. Accuride tests its slides under the American Society for Testing and Materials’ (ASTM’s) standards.
Similar to the team that maintains the Golden Gate Bridge, we are constantly looking for new and improved ways to ensure our slides are the most resilient in the world. For more on our drawer slide finishes, check out the video below!