NORMA Group lead the industry in the development of an extensive range of hose clamps and worm drive hose clamps (WDHC) and remains one of the world's foremost innovators, producers and suppliers to heavy duty engine applications. Our portfolio of hose clamps and WDHC's include constant-tension hose clamps that offers a wide range of diameters, screw types, housings and materials to satisfy the needs and requirements of your applications.