By a long shot, the most frequently asked question about Popco’s suction cups is: How much weight can they support? It’s tougher to answer than you might think.
Many factors affect the weight-bearing capacity of the cups. For example:
Are the cups adhered to a clean surface?
A little grit or grime will weaken the cup's bond.
Will the cups be subjected to movement, such as a swinging cooler door?
Weight in motion is far different than stationary weight.
Will the cups be exposed to temperature extremes, like inside a hot car in summer, or inside a cooler or freezer?
Weight bearing capacity will be diminished under these conditions.
Is the mounting surface uneven or textured?
Such surfaces are far from ideal.
We can’t test for every scenario, so we decided to test the suction cups as we hope they'll be used: under ideal conditions.
For our tests, we clamped a glass mirror to an office door and we made sure that the mirror and our test cups were clean. We then started hanging bags of metal rings, each weighing .95 lbs., from the cups.
To test for both weight and duration, bags were added one at a time. Each bag remained in place for 24 hours before an additional bag was added.
This process continued for weeks and the results of our tests were remarkable. Each style of Popco suction cup was tested and our largest suction cup supported over ten pounds before failing. Our smallest cup supported nearly three pounds.
Another thing our tests revealed was that, in most cases, bending of the cup's stems led to failure before the cups themselves sheared off. Shown above is an SCM-177 suction cup and you can see the stem starting to bend as it supports roughly five pounds.
We’ve compiled our test results and created a reference sheet that will help you determine which of our suction cups is right for your project. Check it out and give us a call if you have questions or if we can help you with an order.
Disclaimer: Our tests were not independently conducted. We recommend that customers conduct their own tests specific to their usage.