MS ERW Pipes And Tubes MS ERW Pipes And Tubes Ratna Steeltech is one of the emerging MS ERW Pipes and Tubes Manufacturer In Ahmedabad. Common sizes for ERW Steel Pipe range from 1/2″ NB to 20″ NB in a variety of lengths to over 40 feet. Surface finishes are available in bare and coated formats and processing can be handled on site to customer specifications.