A screw flat face coupling is a type of coupling used to connect two rotating shafts in mechanical systems. It is designed to transmit torque and rotational motion between the shafts while maintaining alignment and minimizing backlash.

The coupling consists of two halves with flat faces that come together to form a secure connection. The flat faces provide a large contact area, ensuring a tight and rigid connection between the shafts. This design helps to minimize misalignment and reduce the occurrence of vibration and noise.