Self-tightening traction assemblies or snow chains having tensioning devices that can be used with snow chains for attachment to a vehicle wheel to provide traction. The preferred tensioning device including a housing having a top including a set of housing teeth, a bottom and at least one aperture; an actuator interconnected to the housing; a ratchet spool within the housing having a set of ratchet teeth that mate with the housing teeth and a channel between upper and under surfaces to receive at least one cord that is interconnected with the ratchet spool; a tension spring that places a bias on the ratchet spool toward a wind-up direction; and a wave spring. Preferred embodiments include a bracket that can secure the actuator to the housing and provide strength to the tensioning device. The tensioning devices of the present invention can be utilized in a variety of applications not limited to self-tightening snow chains.