Cast Iron and Semi Steel Wheels are made of incredibly strong steel that is highly resistant to abuse and tough environments. Cast Iron wheels are able to withstand high temperatures and can be exposed to water and/or other abusive factors in challenging environments. They can withstand exposure to chemicals, grease and oil. However, one downside is that Cast Iron wheels will rust over time if exposed to fluids and chemicals regularly. This wheel should be specified when excessive load weights are involved and floor protection is not a factor. Its high strength withstands sharp impacts but can also be very damaging to floors. Cast Iron wheels should not be used if noise is of major concern or if loads are fragile as they do not provide for the smoothest rolls. The temperature range on Cast Iron wheels is -45ºF to +180ºF. If metal washers specified: -45ºF to +500ºF (Roller, Ball, and Sleeve bearings only). Cast Iron wheels are available with Precision Ball Bearings, Annular Bearings, Straight Roller Bearings, Tapered Roller Bearings and Delrin Bearings or Plain bores. With a large number of sizes available, a Cast Iron wheel could be the right solution for your demanding application.