In a very basic sense a friction hinge is a mechanism which uses friction to impede rotation or movement of an object. This does not necessarily apply to pivoting about an axis alone, you can have a friction hinge that is a ball and socket type device which has more degrees of freedom. You can see friction hinges in devices such as toys and medical devices, they may look the same and seem to operate the same but the difference is in the engineering behind the performance.  The engineering quantities I am referring to are materials that take high stresses, consistent torque over millions of movement cycles, resistant to temperature, harsh chemicals and abuse. Usually in low cost, low cycle devices little thought goes into life cycles, but in a medical device or rugged laptop, engineering is everything.  So if you are designing a device that needs to have a high quality standard and you need good, consistent performance see us at www.mmtech.us