When subjected to a greater lateral load, a plummer block cannot be reliably secured with the tightening force of mounting bolts alone. To overcome this problem the end faces of the mounting bolt seat are secured with stoppers to lock the plummer block. With the plummer block used in this type of application, the end faces in contact with the stoppers are machined.The housings of NTN plummer blocks are made of class 3 gray cast iron (FC200).  summarizes the mechanical properties of this material. Cast iron materials boasts the greatest vibration dampening capability among various metal materials. They also perform well in a wider operating temperature range of –20 to 300˚C. For application involving shock load and vibration, class 2 spheroidal graphite cast iron (FCD450) or class 3 carbon cast steel (SC450) is used.