Abstract: The mandrel pipe mill shell-transfer system falls into two types, i.e., the overhead crane type and the floor car type.Detailed here in the paper are the structures and operation of these two shell-transfer systems, involving the advantages and disadvantages of each of them.Accordingly, proposals for type selection of such systems are put forward.For mandrel mills with size range under Ф180 mm, it is suggested to use the floor car type shell-transfer system which features lower initial investment and operation costs, higher productivity and easy equipment maintenance.However, it is disadvantageous obviously to use the floor car type shell-transfer system for mandrel mills with size range equal to or over Ф180 mm, it should be determined according to the concrete circumstances.