Comparing How Quickly Steel, Galvanized Steel, Aluminum and Stainless Steel Rust

Even though we typically recommend stainless steel for outdoor applications, we are often asked how well other materials hold up.   It is hard to answer this question because it depends on the environmental factors of the application (climate, humidity, temperature, direct exposure to elements vs. shielded, etc.)  At a minimum though, we thought it would be helpful to run a very simple experiment to show people what typical oxidation looks like at various times.

To begin, we collected the following items necessary for the experiment:

(1) Large Cup of Black Coffee

(2) Gallons of Distilled Water

(1) Salt without Iodine additive

(12) Jars

(4) Stainless Steel Clips

(4) Steel Clips

(4) Galvanized Steel Clips

(4) Aluminum Clips

We used the salt and the distilled water to create a standardized 5% solution of NaCl, know as NSS or neutral salt spray.  From there the experiment is quite simple.  We will hold the control to the side and then at various times in the future we will remove the samples from the jars and compare with the control pieces to compare the oxidation.

Large Cup of Coffee
Steel Clips
Steel, Galvanized Steel, Stainless and Aluminum Clips








Distilled Water
Distilled Water







Table Salt
Table Salt
Jars Filled with NaCl Solution
Jars Filled with NaCl Solution







Submerged Samples
Submerged Steel Samples in Saline Solution
Labeled Samples & Control
Labeled Samples









Z Clip Corrosion Testing Pictures – 1 Day After Beginning

1 Day - Steel Clip
1 Day – Steel Clip
1 Day - Stainless Clip
1 Day – Stainless Clip







1 Day Galvanized Clip
1 Day – Galvanized Clip
1 Day - Aluminum Clip
1 Day – Aluminum Clip