China Alloy Springs is one of the best companies to go to when you need any type of spring created. China Alloy Springs specializes in making heavy duty extension springs. These springs are different from all of the other types of springs because they are more intense. The tension can be very powerful with heavy duty extension springs. Sometimes a project will require so much weight and so force that heavy duty extension springs are the best possible option for the project. If this is the case you may want to consider giving us a call.