This CGA technical report reviews the in-service performance of DOT-3A cylinders to determine their suitability for continued use. A summary and analysis of extensive studies of fracture control is presented to determine if DOT-3A cylinders are more likely to fracture and fragment in service than DOT-3AA specification cylinders. Data on service failures of DOT-3A and DOT-3AA cylinder failures are also compiled and analyzed. The report provides a history of steel cylinder specifications and summarizes the procedures used for fracture and fragmentation control since steel cylinders were first manufactured. TR-2 is the supporting document for CGA PS-16, CGA Position Statement on Suitability of DOT-3A Type Cylinders for Continuous Service.