Renold Ajax is the leading North American manufacturer of Traction Couplings for Subway Rail Cars, having produced more than 20,000 units over the past 35 years for use in many cities in the USA, Singapore, Malaysia, Brazil, and Korea. Renold has analyzed measured wear rates of couplings in service and project a service life of over 8 million miles. In development of new designs, Renold uses a state of the art test cell, which can run the coupling up to full speed and full load, while changing the operating conditions to simulate the dynamics of actual operation on a subway car.