Corrosion resistance plays a decisive role in the functionality and service life of a castor. Moisture, cleaning agents, salts or aggressive ambient air attack unprotected metal parts. Which level of protection is sufficient depends on the environment.
Galvanic Zinc Plating – the Standard
As standard, all sheet steel parts of our castors are galvanically zinc-plated to protect against corrosion. For most applications, this is completely sufficient. Zinc coatings have an important advantage over paint: in the event of minor damage, the coating is not undermined by rust. The zinc corrosion product (white rust) covers bare steel areas and stops corrosion by itself. In steel-zinc connections, the zinc corrodes preferentially due to electrochemical processes.
Zinc-Plated and Painted – Enhanced Protection
Our black series are both galvanically zinc-plated and painted black. As a result, black castors have particularly high corrosion protection.
Aluminum – Corrosion Protection Without an Additional Layer
Aluminum alloys occupy a special position. Aluminum is resistant even without an additional protective layer: it combines quickly with oxygen to form aluminum oxide, which acts like a cover layer and prevents the progression of corrosion. In the event of mechanical damage, this protective layer renews itself within a short time. Due to its lower load-bearing capacity, aluminum is not suitable for swivel castor housings, but is excellent as a material for wheel rims. In combination with stainless steel wheel bearings, particularly high corrosion resistance is achieved in the wheel area.
Stainless Steel – for High Requirements
In environments with higher requirements, you should use castors with stainless steel housings . Chrome-nickel steel AISI 304, which has strong anti-rust properties, is most commonly used for castor housings. For even higher requirements, special products in AISI 316 (V4A) can be used.
Which Protection for Which Environment?
- Dry indoor spaces: galvanic zinc plating is generally sufficient.
- Variable humidity, occasional cleaning: zinc-plated and painted, or aluminum rim with stainless steel bearing.
- Wet areas, cleaning agents, outdoor use: stainless steel AISI 304.
- Aggressive media, food/chemical sector: stainless steel AISI 316 (V4A).
Closely related topics can be found under Hygiene & Cleanliness as well as in our PDF on chemical resistance.