Elastic coupling is usually made of metal cutting rod, commonly used materials are aluminum, stainless steel, engineering plastics. The use of flexible coupling system of parallel or spiral grooves cut to accommodate a variety of errors and accurate transmission of torque. Elastic coupling usually have good performance and price advantage, in many stepper, servo system in the practical application, the elastic coupling is the preferred product. One piece design allows flexible coupling to achieve a zero gap to transmit torque and no need to maintain the advantage. Elastic coupling mainly has the following two basic series: spiral groove type and parallel groove.

Spiral groove type elastic shaft coupling having a continuous loop of the long groove, the coupling has a very good flexibility and small bearing load. It can withstand all kinds of deviation, the most suitable for the correction of angle and axial deviation, but eccentric capacity is rather poor, because at the same time the spiral groove in two different bending directions, can produce large internal pressure, leading to the premature damage of shaft coupling. Despite the length of spiral groove type coupler can bear various deviations in case easily bent, but in torque load under the condition of poetic couplet axis rigid also has the same effect. Torsion load large rotary gap will affect the coupling precision and reduce their overall performance.

Spiral groove type elastic coupling is a more economical choice, the most suitable for low torque is applied, especially in the coupling encoder and other lighter instrument.

Parallel slot type elastic coupling is usually 3 to 5 slots, to deal with the problem of low torque rigidity. Parallel groove into account does not weaken the ability of correcting deviation under the groove cutting short, short groove can make the coupling torque rigidity enhancement and overlapped together, so that it can withstand considerable torque. These properties make it suitable for light duty applications. For example, a servo motor and ball screw connection. But the performance with the groove size increases, the bearing load will increase, but the majority of cases, can be effective enough in protecting bearing. Increase size means increasing under eccentric ability.

Now most of the elastic coupling are made of aluminum alloy material to do, of course also has a stainless steel elastic coupling. Stainless steel flexible coupling in addition to corrosion resistance, but also increase the torque bearing capacity and rigidity, can even reach two times of the aluminum alloy products. However, this increased torque and rigidity to a certain extent will be increased mass and inertia and offset. Sometimes the negative effects will exceed its benefits, so that users have to look for other forms of coupling