Yes, you can technically use a torque wrench for loosening bolts, but it’s strongly discouraged by most manufacturers and mechanics. While it might not immediately break the wrench, it can damage its calibration and lead to inaccurate torque readings in the future, compromising the safety and integrity of your work.

Using a Torque Wrench for Loosening: The Risks and Realities

Many DIY mechanics and even some professionals wonder if a torque wrench can pull double duty as a breaker bar for loosening stubborn fasteners. It’s a tempting thought, especially when you’re faced with a bolt that just won’t budge. However, the consensus among experts is a resounding no, and for good reason.

Why Torque Wrenches Aren’t Designed for Loosening

Torque wrenches are precision instruments designed to apply a specific amount of rotational force, or torque, to a fastener. This ensures that bolts are tightened to the manufacturer’s exact specifications. This precision is crucial for everything from engine components to wheel lug nuts, where over-tightening or under-tightening can lead to serious problems.

The internal mechanisms of torque wrenches, whether they are click-type, beam, or digital, are calibrated for applying torque in one direction. When you use them to break a bolt loose, you’re often applying force in the opposite direction and potentially exceeding the wrench’s designed limits.

The Impact on Calibration

The primary concern with using a torque wrench for loosening is the detrimental effect on its calibration. When you apply excessive force to break a bolt free, you can bend or damage the delicate internal spring or mechanism. This damage might not be visible, but it will throw off the wrench’s accuracy.

Imagine a highly sensitive scale. If you consistently place objects far heavier than its intended maximum on it, even if it doesn’t break, its readings will become unreliable. A torque wrench works similarly. Once its calibration is compromised, it can no longer accurately measure or apply the correct torque.

Potential for Damage to the Wrench Itself

Beyond calibration issues, there’s also the risk of physically damaging the torque wrench. Many click-type torque wrenches have a mechanism that releases a "click" when the set torque is reached. Applying significant force to loosen a bolt can overwhelm this mechanism, potentially breaking internal components.

This is especially true for beam-type torque wrenches, where the bending of the beam is what indicates torque. Forcing a tight bolt could bend the beam beyond its elastic limit, permanently deforming it.

What Happens When You Loosen with a Torque Wrench?

When you use a torque wrench to loosen a bolt, you’re essentially using it as a lever. If the bolt is particularly seized, you might need to apply a considerable amount of force. This force can:

• Exceed the wrench’s maximum torque setting: Even if set to its highest value, you might need more force to break the bolt free.
• Apply force in the reverse direction: The internal components are not designed for this stress.
• Cause sudden jolts: The moment the bolt breaks free, there’s often a sudden release of tension, which can shock the wrench’s mechanism.

The Right Tool for the Job: Using a Breaker Bar

For loosening stubborn bolts, the correct tool is a breaker bar. A breaker bar is essentially a long, non-ratcheting handle designed specifically for applying high leverage to break fasteners loose. They are built to withstand the significant forces required without damaging their internal mechanisms or calibration.

A breaker bar allows you to apply steady, controlled force. If a bolt is still too tight for a breaker bar, you might consider using penetrating oil, heat, or a specialized impact wrench.

When is it "Okay" (with caveats)?

In a pinch, if you absolutely have no other option and the fastener isn’t excessively tight, you might be able to use a torque wrench for loosening. However, this should be an absolute last resort. If you do this:

• Use the lowest possible torque setting (though this offers minimal protection).
• Be prepared for the possibility of damaging the wrench.
• Immediately have the torque wrench recalibrated by a professional service after such an event, regardless of whether you think it was damaged.

The Long-Term Cost of a "Quick Fix"

While using a torque wrench to loosen a bolt might seem like a time-saver or a way to avoid buying another tool, the long-term consequences can be far more costly. A damaged torque wrench can lead to:

• Incorrectly tightened fasteners: This can cause premature wear on parts, vibrations, leaks, or even catastrophic failure.
• The need for expensive recalibration or replacement.
• Compromised safety: In critical applications, an improperly torqued fastener is a serious safety hazard.

People Also Ask

### Can a torque wrench break if used to loosen a bolt?

Yes, a torque wrench can potentially break if used to loosen a bolt, especially if the bolt is seized and requires significant force to break free. The internal mechanisms are not designed to withstand the high, sudden forces often needed for loosening, which can lead to component failure.

### What is the difference between a torque wrench and a breaker bar?

A torque wrench is designed to measure and apply a precise amount of rotational force for tightening fasteners to specific specifications. A breaker bar, on the other hand, is a long, non-ratcheting bar used solely for applying high leverage to loosen stubborn fasteners, without measuring torque.

### How do I know if my torque wrench is damaged?

Signs of a damaged torque wrench include inconsistent clicks, a lack of a click when reaching the set torque, or a general feeling of looseness in the mechanism. The most reliable way to check is to have it professionally calibrated, as subtle damage can affect accuracy without obvious external signs.

### Is it bad to use a click-type torque wrench in reverse?

Using a click-type torque wrench in reverse is generally bad practice. The internal mechanism is calibrated for applying torque in the forward direction. Applying force in reverse can damage the spring and calibration, leading to inaccurate readings when you use it for tightening.

### How can I loosen a very tight bolt without a breaker bar?

If you don’t have a breaker bar, you can try applying a penetrating oil and letting it soak, using a rust penetrant, or gently tapping around the bolt head with a hammer to help break the corrosion bond. In some cases, controlled heat applied to the surrounding area can also help. If these methods fail, it’s best to acquire a breaker bar.

Conclusion: Prioritize Precision and Safety

In summary, while you can physically use a torque wrench to loosen bolts, it’s a practice that carries significant risks to the tool’s accuracy and longevity. For the sake of precision, safety, and the lifespan of your tools, always opt for a breaker bar when loosening stubborn fasteners. Investing in the right tool for each job ensures your work is done correctly and safely