Steel Midsoles – A Must-Have in Your PPE

In any industry that requires personal protective equipment (PPE), steel midsoles are essential in ensuring the guaranteed safety of both yourself and your workforce. These midsoles, also referred to as ‘protective insert plates’, protect against sharp objects encountered on site – such as nails, glass, needles, and metal fragments. 

These ‘sharps’, aside from being painful and having the potential to cause great harm, can drive contamination (dirt, rust, oil, etc.) into the foot – adding the risk of infection to any injury. 

There are two types of midsoles found in safety footwear. These are steel (metallic) and composite (non-metallic). Metallic midsoles are foot-shaped pieces of steel cut in one shape from a roll of steel sheeting. They are generally around 0.5mm thick and have a degree of flexibility that makes them comfortable and easy to wear.

Stainless steel (also called ‘high chromium steel’) midsoles will not corrode or break down over time. These midsoles typically contain a minimum of 10.5% chromium – an element that prevents corrosion and deterioration of steel. 

Steel midsoles are put through a series of thorough and rigorous tests to ensure that they meet acceptable industry standards. The first of these tests involves a 4.5mm nail which is driven into the shoe at a force of 1100N. In order to pass this test, the nail must not pierce the test piece at all.

The second test dictates that these midsoles must undergo one million flexes to make sure that they do not show any signs of cracking, delaminating, or disintegrating. Steel midsoles are also tested for corrosion resistance by spending 48 hours in a 1% sodium chloride solution. 

Once all of these tests have been successfully completed, shoes with these midsoles are ready to enter hazardous work environments and protect your valuable workforce. 

Kaliber prides itself on being one of the first safety footwear manufacturers to include steel midsoles as a standard in its range of products. To view our full range, visit