5) What is the sheet metal operation if reducing the diameter of the pipe for joining to same diameter of other pipe?

6) Which is the type of machine to perform the sheet metal operation like beading, crimping and corrugating?

7) What is the operation of forming a sheet metal into a series of straight parallel alternate ridges and grooves?

8) What is the operation on cylindrical sheet metal objects to provide stiffness for reinforcement or ornamentation?

9) What type of machine is used for double hemming process?