Flexible couplings allow transmission of rotational force between two shafts with a slight tolerance for misalignment. Jaw couplings connect the shaft of a motor to the shaft on a stationary machine. Two jaws interlock around a coupling spider, which can be soft to absorb shock, or firm to transmit torque, to create a complete coupling. Sleeve couplings feature an internal tooth structure on both the motor and stationary machine flanges, interlocking with external teeth on each side of the sleeve insert to completing the coupling. Inserts allow for shock loads and misalignment. Tire couplings connect two shafts when a tire coupling hub is attached to each shaft and a tire coupling element is installed between them. Coupling elements absorb vibration and heavy shock loads. Chain couplings connect two high-torque shafts in constant rotation by mounting and aligning a chain coupling sprocket on each shaft, then joining them with a compatible double strand roller chain. Grid couplings connect the shaft of a high-torque motor to the shaft on a stationary machine. Two hubs interlock with a single shock absorbing grid insert, then a cover is installed to create a complete coupling. Flexible rubber couplings allow increased misalignment in low torque applications and feature one-piece design with a set screw coupling collar at each end, and a rubber insert permanently joining the two ends.