Typically, no modifications are required for an ambient down to approximately -20 ºC [-4 ºF] . For ambient temperatures below that, however, the first consideration is lubrication. For grease-lubricated bearings, make certain the grease is suitable for the ambient and is compatible with the manufacturer’s recommendations. When ambient temperatures fall below -25 ºC [-13 ºF] , additional consideration must be given to the types of materials used in manufacturing. The most common material changes will be in fans, shafts, frames and end brackets. Fans may need to be changed from plastic to either steel or bronze. Shaft material will likely be changed from a standard material, such as AISI 1040, to a high-strength alloy like AISI 4140. Cast-iron frames and end brackets will typically be changed from grey iron to ductile iron due to the brittle nature of grey iron in low-ambient conditions. These material changes will need to be made at various ambient ranges between -25 ºC and -60 ºC [-13 ºF and -60 ºF] , depending upon the standard material and application.