https://nakedbinderblog.com/2013/10...ring-binder/Different quality metal can be used in the making the rings. I have also noticed that some mechanisms take a large amount of force to open while others do not. This may be due to mechanism design, age, and/or use of the mechanism over time. Or it may be the quality of the binder.
But if you have a binder of lesser quality and no boosters it may be a recipe for alignment problems. This issue might be decreased if non-booster binder are opened with the middle ring instead of the top or bottom rings. (Force applied in a more balanced method instead of torqueing the mech from just one end.)
Here is a test that can demonstrate the variance between binders (often from the same manufacturer). Open binder and lay flat on desk. Using the top or bottom ring, slowly start pulling the ring open. Note how far you can open the ring before the force finally overcomes the resistance to pop all of them open. If you can pull the ring open a bit without the mechanism activating, chances are good that the rings will eventually become out of alignment. It might also be helpful to check to see if the amount of force required to open the mechanism is different for each ring.
Don