Product details:
Mechanical Cooling Fan18 in Fan4 Blade5/8 in PilotUniversal Bolt PatternSteelBlack PaintEachSteel high RPM fans are available in 15", 18" or 19". All have a universal bolt pattern with a 5/8" pilot hole. Riveted reinforcement plate adds strength and high pitch 32 degree blades increase airflow. Painted black to resist corrosion.