Choosing Torque Wrenches

How to choose a good torque wrench? According to different torque values, select a torque wrench accordingly. We recommend users choose a torque range in the middle of the torque wrench, i.e., between 1/3 to 2/3 of the maximum torque. For instance, when tightening screws with a 100Nm torque, we suggest using HAZET's 5122-3CT torque range of 40-200Nm. This ensures the spring structure doesn't frequently reach the critical point, offering better protection for the torque wrench and enabling long-term use.

Why use a torque wrench to tighten screws instead of loosening them?

Torque wrenches are more of a measuring tool than a mere tool. While we can typically remove and install most screws with a ratchet or a regular wrench, the force applied is determined by an individual's strength, which affects the tightness of the screw. For critical components like machinery, a specific torque value is required to ensure the screw is neither damaged nor fails to meet the necessary usage requirements. During disassembly, there's a momentary intense force, even with newly installed screws, which can be significantly greater than the torque applied during installation. This can easily lead to damage to the torque wrench.

2. Torque Wrench Precision Re-calibration

Torque wrenches, like cars, require maintenance after a certain mileage or period of use. Typically, after 5,000 uses or six months, the torque wrench needs to be recalibrated for accuracy. This should be done by a professional using specialized equipment to extend the wrench's lifespan. To achieve this, it's important to reset the torque value to zero after each use, preventing the spring from being compressed for extended periods, which can lead to fatigue and a shorter lifespan for the torque wrench.

Torque Wrench Routine Maintenance

If the preset torque is reached and pressure is continued, it can cause damage to the workpiece.

Before setting the torque value, ensure the torque wrench is in a LOCK or UNLOCK state.

Generally, torque wrenches are calibrated and tested upon manufacturing, with varying accuracy across different models. The accuracy at any torque setting is ±4%, ±3%, or ±1%. As this is a high-precision measuring instrument, only professionals should perform maintenance, and it should never be soaked in any liquid, as it could affect the internal lubrication.