A torque or friction hinge is a hinge that offers resistance to the pivoting motion. That resistance can be such that it slows the movement for reasons of safety or aesthetics or that it actually arrests movement to the extent that the pivoting object is held motionless in the chosen position.
Examples of this kind of hinge are now common, typically in a laptop screen. However the challenges in manufacturing them are not trivial. The friction arises when two surfaces are in mechanical contact. A rusty iron hinge can be quite effective but loosens up quickly when wiggled. What is wanted is a hinge where the degree of resistance to movement is consistent and controllable over a long duty cycle. Often a second material is used where the friction coefficient is more desirable and some mechanism to maintain a consistent pressure within the joint.
When installing a torque or friction hinge the weight of the door or panel needs to be known and also the length of it from the point of pivot. Torque is measured in kilograms force per centimetre or kgf/cm, so where a 1kg panel is 50cms wide a hinge with a torque rating of at least 50kgf/cm would be used to hold it motionless. Sometimes it may be enough just to damp the motion in which case a lower value could be used. Hinges can also be used in multiples so that two of the above hinges would give a combined yield of 100kgf/cm. Our torque calculator takes some of the effort out of this calculation.
A torque hinge like the STFH comes in a range of torque values from 5kgf/cm to 58kgf/cm and can be used singly or in multiples. Great attention to detail allows a minimum of springback, that annoying tendency of friction hinges to retreat slightly from where you have placed them. Being made from stainless steel it is ideal for use in manufacturing or industry.
The HG-IT is also made from stainless steel and has a torque rating of up to 70kgf/cm using a phosphor bronze friction collar. It is often used to support VDUs or instrument panels. It also comes with an optional plastic cover.
The HG-TA covers similar duties but is handed and having a different geometry is suited to installation at opposite ends of a panel or door.
There was much excitement in the office (you’re right, we should get out more..) when two new dual axis torque hinges arrived, the HG-T30S15 and the HG-T70S30, these allow a monitor to be positioned with tilt and rotation perfect for screens attached to machinery where operators may wish to view the screen from a variety of stations. They are so new they are not yet on the website so if you want more information please ring the warehouse.
Torque hinges fit into a family of hinges that include detent hinges and damped hinges where the hinge often does the job of both hinge and stay. You can see more on the website or order a free catalogue to keep on your desk.