Friction hinges have quite a few modes of operation. Almost all friction hinges rely on a physical interference between mechanical elements to achieve their holding ability. We can achieve the interference by creating a round spring cylinder, called a wrap-band, that has a cylindrical shaft which is inserted into it resulting in friction hold. This method is popular with laptop computer makers because it can be made compact and if engineered properly it can withstand many cycles of rotation and hold the computer screen in place and never fall from the position. If you think of all the applications, lcd screens, lids, doors, protection screens, camera holders, lighting fixture, aerospace head rests, medical and hospital grab bars a friction hinge is probably embedded in it. The challenges faced in friction hinge design are quality and price. We need to design the friction hinge to achieve a consistent holding torque at a reasonable price and to last for the life of the product. Friction hinge quality is achieved though the attention to detail in engineering, material choices, lubrication choice (if required) and testing. At Mechanical Motion Technologies we evaluate each application independently. One size fits all is not very prevalent in the technical products we design our friction hinges for. Not every lid, lcd or whatever your component is has the same torque holding requirements. Once we calculate the torque requirements and range of motion for your product we can engineer a consistent torque from hinge to hinge that will result in a stable product that will last according to your requirements. I have discussed a specific type of friction hinge here today called wrap-band technology. The friction hinges we design can utilize this technology, but I have more advanced technologies which I use to design friction hinges which has unique advantages for todays new applications. See our web page at www.mmtech.us for product images of emerging technologies which just may give your new product the feature it needs.