Yes, it is generally safe to use a torque wrench for loosening bolts, but with important caveats. While designed for tightening, a torque wrench can be used for loosening, provided it’s a click-type model and you follow specific procedures to avoid damage to the tool or the fastener.

Using a Torque Wrench for Loosening: Is It Safe?

Many people wonder if their trusty torque wrench can be used for more than just tightening. The short answer is yes, but it’s crucial to understand the nuances. Using a torque wrench to loosen fasteners is a common practice, especially in professional settings where precision is paramount. However, not all torque wrenches are created equal, and improper use can lead to tool damage or inaccurate readings in the future.

Understanding Torque Wrench Functionality

Torque wrenches are precision instruments designed to apply a specific amount of rotational force, or torque, to a fastener. This ensures that bolts and nuts are tightened to the manufacturer’s recommended specifications, preventing over-tightening (which can strip threads or break bolts) and under-tightening (which can lead to loosening and component failure).

Click-Type Torque Wrenches and Loosening

Click-type torque wrenches are the most common and generally the safest to use for loosening. When you reach the set torque value during tightening, the wrench audibly "clicks" and often slips slightly, signaling you to stop.

When loosening, the click mechanism still functions. You set the wrench to a torque value, and when you apply force to loosen, the wrench will click when it reaches that set resistance. This prevents you from applying excessive force that could damage the bolt head or the threads.

Beam-Type and Dial Torque Wrenches

Beam-type and dial torque wrenches are more sensitive. While they can be used for loosening, it’s easier to over-apply force and potentially damage the wrench’s calibration or the fastener itself. These types are less forgiving when used in reverse.

Best Practices for Loosening with a Torque Wrench

To ensure safety and preserve the integrity of your torque wrench and fasteners, follow these guidelines:

• Use a Click-Type Wrench: This is the most important rule. The click mechanism provides a natural stopping point.
• Set to the Lowest Setting: If possible, set your click-type torque wrench to its lowest torque setting before attempting to loosen. This minimizes the risk of applying excessive force.
• Listen for the Click: Just as you stop when you hear the click during tightening, pay attention to the click when loosening. This indicates the torque required to break the fastener free.
• Apply Smooth, Steady Force: Avoid jerky movements. Apply consistent pressure to the wrench handle.
• Do Not "Zip" or "Shock" the Fastener: Never use a torque wrench like a breaker bar to shock a stuck bolt loose. This can damage the internal mechanism of the wrench.
• Inspect the Fastener: After loosening, check the bolt and threads for any signs of damage, such as stripped heads or stretched bolts.
• Re-Calibrate if Necessary: If you frequently use your torque wrench for loosening, consider having it professionally calibrated more often to ensure its accuracy for tightening applications.

Why Not Use a Breaker Bar?

A breaker bar is a long, non-ratcheting bar designed specifically for applying high torque to loosen stubborn fasteners. It offers superior leverage and is built to withstand the forces involved. Using a breaker bar for loosening is generally preferred because:

• It’s designed for the task: Breaker bars are robust and intended for high-force applications.
• It protects your torque wrench: Repeatedly using a torque wrench for high-force loosening can damage its calibration and internal components.
• It prevents accidental over-tightening: You’re less likely to inadvertently apply too much force that could damage threads or the fastener.

Potential Risks of Using a Torque Wrench for Loosening

While generally safe with a click-type wrench, there are still risks:

• Damage to the Wrench: Excessive force, especially with non-click types, can damage the calibration mechanism.
• Damage to the Fastener: Applying too much force can strip bolt heads or damage threads.
• Inaccurate Future Readings: A damaged torque wrench will not provide accurate torque values for tightening.

When to Avoid Loosening with a Torque Wrench

• Stuck or Rusted Bolts: If a bolt is extremely tight or rusted, a breaker bar is a much safer and more effective tool.
• Non-Click Type Wrenches: Avoid using beam or dial torque wrenches for loosening unless absolutely necessary and with extreme caution.
• High-Torque Applications: For very high-torque fasteners, a dedicated impact wrench or heavy-duty breaker bar is recommended.

Can a Torque Wrench Be Damaged by Loosening?

Yes, a torque wrench, especially a click-type, can be damaged if used improperly for loosening. The primary risk is exceeding the wrench’s designed capacity or applying force in a way that compromises its internal calibration mechanism. This is why using the lowest setting and avoiding jerky motions is crucial.

What Torque Setting Should I Use for Loosening?

For a click-type torque wrench, it’s recommended to set it to its lowest torque setting when loosening. This provides a safeguard against applying excessive force. The wrench will click when it reaches that set resistance, indicating the torque needed to break the fastener free.

Can I Use a Torque Wrench as a Breaker Bar?

No, you should never use a torque wrench as a breaker bar. Breaker bars are specifically designed to withstand the high forces required to loosen stubborn fasteners. Torque wrenches are precision instruments for applying controlled torque during tightening, and using them for high-force loosening can easily damage their calibration and internal mechanisms.

Conclusion: A Tool for Specific Situations

In summary, using a click-type torque wrench for loosening bolts is generally safe and acceptable, provided you adhere to best practices. It’s a useful technique when you need to break a fastener free at a controlled torque, especially in situations where over-torquing could cause damage. However, for severely stuck fasteners or when dealing with very high torque values, a dedicated breaker bar or impact wrench is always the superior and safer choice. Always prioritize the longevity of your tools and the integrity of your fasteners.

People Also Ask

### Is it okay to use a torque wrench in reverse?

Yes, it’s generally okay to use a click-type torque wrench in reverse for loosening, but with caution. Always set it to the lowest torque value and apply smooth, steady force. Avoid using it like a breaker bar, as this can damage the wrench’s calibration.

### Can loosening a bolt damage a torque wrench?

Yes, loosening a bolt can damage a torque wrench if done improperly. Excessive force, especially with non-click types, or using it as a breaker bar can compromise its internal calibration mechanism and