Part 2 in a 10-part series on specifying hinges
Last week we discussed how strength is often one of the first considerations when choosing a hinge. But just how strong a hinge do you need?
Here at Southco we use four factors that can help when getting started.
1. Weight: Determine the weight of the door. If you can’t physically weigh the door on a scale, a quick estimate can be calculated with the following formula: length x width x height x density. The heavier the door, the stronger the hinge you will need.
2. Center of Gravity: Determine the center of gravity (Cg) of the door. If the door is uniformly thick, the Cg will lie dead center. Unfortunately, most doors aren’t uniform.
So here’s a few simple steps for determining the Cg, regardless of door shape.
(A) Hang the door from one corner so it pivots freely
(B) Attach a plumb line to the pivot so the line hangs freely
(C) Mark the line on the door
(D) Repeat twice more, hanging the door from a different corner each time
The Cg is where all three lines intersect.
3. External Loads: Consider the added weight of components that might be fastened to the door: electronics, cooling equipment, hooks, etc. And don’t forget loads applied by wind, moving objects or forces generated by gasket compression or pressure within an enclosure.
4. Test: Whenever possible, test the hinge in the application. Variations in mounting and build tolerances often mean that one hinge takes the brunt of the load. We need each hinge to share equally in the effort!