pipe having the combination of specified outside diameter and specified wall thickness is defined as special plain end pipe. other combination given in this table are defined as regular plain-endpipe. pipe that has a combination of specified out side diameter and specified wall thickness that is intermediate to the tabulated values is considered to be special plain end if the next lower tabulated value is for special plain end pipe, other intermediate combination to be regular plain end pipe.
ERW steel pipe are length, width, height, welding gap, radius, diameter etc. According to the nature of the requirements the size of the rectangular steel pipes and tubes can be altered.