Prevailing Torque and Two Types of Thread Lockers

The miniature screws market has been flourishing lately with the high demand for smaller electronic components. One of the difficulties manufacturers of smartphones and other handheld devices have with tiny screws is the task of fastening them securely when faced with potential vibration or external forces unfastening the screw. The way small screws have overcome this obstacle is with thread lockers.

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The Two Types of Thread Locker
Today, to overcome vibrational stress and other outside forces, there are two primary types of thread lockers used to fasten micro screws:

• • Reactive thread lockers use a dry epoxy-based encapsulated adhesive on the screw thread. When fastened, the threads pinch the encapsulated epoxy, releasing it, and the seal undergoes a locking process. On certain reactive thread lockers, the chemical adhesive also expands to give a watertight seal. This type of thread locker provides massive amounts of staying power, as it is essentially a technologically advanced glue.

• Inert thread lockers utilize the concept of prevailing torque to secure screws. When locked into place the screw becomes resistant to both vibrations and shock related slipping. Inert thread lockers are made for components that might need to be unscrewed in the future, so they focus on prevailing torque over breakaway torque.

what is prevailing torque?
To understand prevailing torque, first, you need to understand your breakaway value. After you apply your thread locker, hand tighten your screw. Let it sit for a day to properly cure. When you unscrew it, the force (measured in torque) that it takes to overcome the static friction is your breakaway value. Once that has been overcome, you can determine your prevailing torque from the thread locker. Continue to unscrew a quarter of a rotation at a time, taking note of the amount of force required. That number is your prevailing torque, or how much extra force is required with the presence of an inert thread locker.

One of the features you have control over with our custom screws is prevailing torque. However high or low you require the prevailing torque of your screw to be rated for, it is possible. Talk to us today to learn more about the miniature magic of micro screws, and to design your custom screws for any project.