Guide: The Influence of RPM on Torque Performance

When assembling parts with an electric torque screwdriver, numerous factors come into play to ensure precise torque control. Considerations include the hardness of the joint, the material used, and whether the screw is lubricated or treated with a locking patch. Surprisingly, one often-overlooked factor is the RPM setting of the tool. 

Do changes in RPM affect the torque applied to a joint? In short, yes. RPM settings can indeed contribute to the torque applied. However, several variables must be taken into account. It's crucial to document settings and ensure they remain unchanged after validation. Consistency in RPM settings is vital for calibration validation and correlation.

Here are some variables to consider:

• Higher RPM: Less energy is applied to the joint as the force is present for a shorter time. Higher RPM may lead to increased inertia, although the net differences depend on the mass of the force generated.
• Lower RPM: More energy is applied to the joint as the force is present for a longer time. Lower RPM can result in less inertia, again depending on the mass of the force generated.

In some scenarios, the net differences may be insignificant, while in others, they may be more pronounced. Therefore, it's best to check residual torque at the joints and develop a formal and consistent plan for setting and validation.

Three Proven Methods of Verifying Torque Specifications

Once a torque specification is established, auditing the joint is essential to ensure the product has been fastened correctly. It's crucial to audit the joint for accuracy and to uphold the product's quality, safety, and reliability. Failure to tighten a fastener properly can lead to catastrophic or latent failures. Insufficiently torqued fasteners may vibrate loose, while excessive torque can strip threaded fasteners. Many companies must ensure that proper torque is applied to meet ISO 9001 Quality Standard requirements.

Here are three common methods for accurately verifying torque:

1. First Movement Test: Tighten the fastener and slowly apply force to the torque measuring tool until the first movement in the fastener is noted. This indicates the original torque applied to the joint and is the best way to determine residual torque.
2. Loosening Test: Apply torque in the direction that loosens the fastener until it breaks loose. The torque reading indicates the approximate torque applied to the joint.
3. Marking Test: Tighten the fastener and mark the surface clearly. Loosen and retighten until the marks align. The torque required to return the fastener to its original location serves as a reference for the original torque applied.

Residual torque is the tension that remains in a joint after fastening a threaded fastener. Checking torque after assembly verifies that adequate torque was delivered to the fastener and may detect missed or loose fasteners or joint relaxation. However, differences in friction between rundown and static conditions must be considered when engineering a residual torque specification.

The equipment used for these testing methods includes dial screwdrivers, dial wrenches, and torque testers with a Rotary Torque Sensor or Torque Screwdriver Sensor to move the fastener.

The Mountz Advantage 

At Mountz, we understand the importance of human customer support. That's why our experienced team takes the time to understand your application requirements comprehensively. Drawing on our extensive industry experience, we offer personalized recommendations to streamline your assembly processes and enhance efficiency.

Mountz stands out in terms of durability. We know that preventing downtime is paramount to your success, so our tools are built to last. Rigorously tested to meet the highest standards, our products deliver unmatched reliability, ensuring your operations run smoothly without interruption.

Trust Mountz for industry-leading torque solutions designed by experts, backed by exceptional customer support, and built to withstand the demands of your assembly processes. Contact us today and experience the Mountz advantage first-hand.