How to use lid hinge moment estimate
What this calculation does
This estimate calculates the static moment at a hinge line for a uniform rectangular lid whose center of gravity lies at half its depth.
Enter lid weight and the full distance from the hinge line to the far edge for the horizontal lid model.
Enter the measurements
- Lid weight: Use the lid weight in pounds.
- Hinge line to far edge depth: Measure full lid depth from hinge to far edge.
Formula and variables
For a uniform rectangular lid with its hinge along one edge, static moment = lid weight × full lid depth ÷ 2, because its center of gravity is at half-depth.
Moment = weight×depth÷2 because the assumed center of gravity is at half-depth. The displayed unit is inch-pounds.
Read the result
A 10 lb uniform lid 20 in deep produces a 100 in-lb static moment in this model.
Worked example
Inputs: 10 lb uniform lid, 20 in deep
- Center-of-gravity distance = 20÷2 = 10 in.
- Moment = 10 lb×10 in = 100 in-lb.
Expected result: 100 in-lb static moment
Frequently asked questions
Does this size or rate support hardware?
No. It is not a hardware rating, support count, safety factor or dynamic estimate.
What if the lid is not uniform?
The half-depth center assumption would not describe that lid; this model does not accept its center of gravity.
Conditions, presets and technical notes
Assumes a uniform rectangular lid in the horizontal position, with its center of gravity at half its depth. It is not a lid-support count, hardware rating, safety factor or dynamic slam estimate; select hardware using its manufacturer instructions.