Semi-Bridge Coupling is a most use for coupling sleeves in market, product features as follow:

• Small non-threaded bridge in the center

• Steel cannot thread past bridge area

• Smaller diameter steel end portions fit together in the center bridge area of the coupling

• Semi-bridged couplings are most suited to high torque machines

• Most rope and HM threaded couplings are semi-bridged.

T38-190 semi-bridge type coupling 

For more details please watch PDF online: Coupling Sleeves Catalogue