High Temperature Wheels with a prefix “NP” in the part number are made of nylon mixed with glass fiber. They perform best in moist heat applications such as in smokehouses, moist heat bakery and autoclave applications and around water and steam such a pressurized steam-autoclave. Temperature Rating: Up to 425° F for 30 minutes MAXIMUM continuous operation. Then allow to cool to room temperature. If used above 425° for more than 30 minutes continuous operation it will reduce the life of the wheel. High Temperature Glass-Filled Nylon wheels are not recommended for dry heat applications because once the moisture content of the wheel gets to zero, the wheel will shatter.