A friction hinge is also referred to as a torque hinge, friction clutch or friction engine. A friction hinge is usually used to hold a pivoting member in a set position until acted upon by another force which exceeds its’ rated torque rating. Common applications are all around us in our everyday lives, but they are embedded in a host system to hide them.  We design them for use in notebook computers, lcd applications, cell phones,medical devices, aerospace systems, computer racks, advertising components, recreational vehicles, cabinet doors, gate systems and automotive components like armrests and visors.  What differentiates friction hinges is the mechanical means in which the friction is engineered to hold the pivoting member in place.  Most applications create frictional hold by having interference between 2 components which exert a force on each other to impede movement.  The amount of torque produced is a function of the interference among other variables such as material, lubrication, contact area and temperature of the environment it is used.   Of course different applications require different materials for their construction.  Extreme high temperatures might require a steel or carbon impregnated friction element.  A hinge for a laptop might need high cycle life of 50,000+ without loosing appreciable torque. Clean room applications need a hinge which must not particulate past a certain criteria. Some hinges must not conduct electricity, have any backlash or produce any noise over their useful life. At Mechanical Motion Technologies we can design for your specific application and specifications. Contact us to discuss your application at www.mmtech.us