Coupling Bolt Hole Diameter Not Applicable Bolt Material Steel Finish/Coating Zinc-Plated Fitting Nominal Pipe Size 4 in Fitting Type Coupling For Movement Type Vibration Maximum Operating Pressure 150 psi Overall Length 6 1/2 in Pipe Fitting Material Steel Seal Material Buna Seal Type Included Self-Restraining Application Chemical Plant Construction Engine Construction Gear Unit Construction Power Station Construction Railway Construction