MRO Magazine

Feature

Why Stainless Steel Rusts

Most of us think of stainless steel, like that used in a wide variety products, including hand tools, as -- literally -- stainless or non-rusting. Yet sometimes, rust will form on these products and t...


Most of us think of stainless steel, like that used in a wide variety products, including hand tools, as — literally — stainless or non-rusting. Yet sometimes, rust will form on these products and tools just — like it does on conventional steel.

How does rust form on stainless steel?

Many hand tools made of stainless steel are corrosion-resistant. However, extraneous rust can occur if stainless steel is handled incorrectly, meaning if it is exposed to non-stainless steel elements. The results are visual damage and functional loss due to pitting corrosion. In such cases, the advantages of stainless steel products are ineffective. In more extreme cases, rust contamination can lead to serious safety defects, complaints and extra costs.

What causes rust?

Extraneous rust is caused by tools made from conventional steel. Even the hardest tools produce wear debris that leaves adhesive steel particles on the stainless steel surface. These particles turn to rust when exposed to oxygen.

How can rust be prevented?

Use like with like. Rust is preventable when stainless steel tools are used, since stainless steel products require stainless steel tools. This is the only way of avoiding wear debris produced by conventional tools, which causes extraneous rust.

Stainless steel tools should be stored separately from conventional tools and be only used for stainless steel screws.

Are stainless steel tools suitable for the shop floor?

It depends. One tool manufacturer, Wera Tools, has developed a special production process to ensure that its Kraftform stainless tools meet the same hardness requirements as conventional tools. The tools are vacuum ice-hardened to give them the hardness required for industrial applications.

What is the need for stainless steel fastening tools?

There is an increasing demand for stainless steel products that require stainless steel fasteners, and when the fasteners form rust, it lends to unsightly applications. Stainless steel tools should be used with these fasteners to prevent unexpected corrosion.

Adapted from Kraftform’s Stainless Fact Sheet, courtesy of Wera Tools Inc., Stoney Creek, Ont.

Low-vibration power tools

More should be done to encourage the use of low-vibration handheld power tools, according to Brammer plc, a European tools and MRO products distributor. It wants to help manufacturers raise the profile of low-vibration tools, including sanders, grinders, disc cutters, hammer drills, chipping hammers and needle guns.

The differences between standard and reduced-vibration power tools are marked. For example: the standard Bosch GWS20-230 230 mm angle grinder has a 5.5 m/s2 principal axis vibration. By comparison, the new Bosch GWS21-230HV 230 mm angle grinder with side and trigger handles that are vibration damped produces less than 2.5 m/s2 of principal axis vibration.

Long-term power tool use can lead to health problems such as hand-arm vibration syndrome (HAVS), which can be severely disabling. It affects the nerves, blood vessels, muscles and joints in hands, wrists and arms.

Over-exposure to hand-held power tools can also lead to vibration white finger, where the tips of the fingers turn white, then red, and are painful on recovery.

According to Brammer tools and maintenance division manager Ian Lofthouse, “This is going to be a hot topic, and with health and safety more important than ever, more should be done to get people to start using low-vibe power tools.”

In Europe, It is estimated that around five million workers are exposed to HAVS, and the introduction in 2005 of the Control of Vibration at Work 2005 regulations requires employers to reduce the risk of prolonged exposure to vibration.

“That means it’s not just something employers might like to do,” Lofthouse said. “It’s a requirement.”