General Torque Guidelines
The reference guide to the right contains common application torque ranges for the most common cap sizes. This is a general guide only; the proper application torque range for your cap may be different from what is listed in the chart. Your cap and bottle vendor is the best source for you to attain the actual application torque specification for your particular cap and container.
To properly seal a container, it is important to not over-torque or under-torque the cap. Many people believe the tighter the cap, the better the seal; this is not the case. Over tightening a cap will cause an uneven seal on the container and is a common cause of leakage. Of course, under tightening a cap will also cause leakage.
For most companies verifying the torque they are applying to their caps is not necessary. An estimation of the proper amount of torque is fine and they can adjust the torque setting on their capping machine to apply the level of tightness they feel is appropriate.
For companies that need to comply with internal quality controls, industry regulations or government regulations, it is critical that they tighten their caps within the specified application torque range. The Method of Test for Closure Torque was developed to guide companies through this process. This procedure explains in detail how to calibrate a capping machine to ensure that you are applying the correct amount of torque onto your caps. Follow this link to learn more about the Method of Test for Closure Torque and to watch a video tutorial that will take you step by step through the process.
* Torque is measured as inch.lbs.
Cap Size (MM)
Onto a Plastic Container
Onto a Glass Container