I remember standing in my garage, staring at a stubborn bolt on my old lawnmower. It was seized tighter than a miser’s purse strings. My toolbox was full of wrenches, but my mind kept drifting to that fancy torque wrench sitting on the shelf. It’s a precision instrument, right? So, can I use a torque wrench to loosen a screw? It’s a question I’d wrestled with myself, and frankly, the online chatter offers a lot of confused noise.
Most folks just grab the biggest wrench they can find and heave. But when you’ve dropped a decent chunk of change on a tool designed for accuracy, you start to wonder about its limits, or more importantly, its misuse. I’ve been there, fumbling with tools and wondering if I’m about to break something expensive.
Why You’re Even Asking About Loosening with a Torque Wrench
Let’s be honest, most of us end up with a torque wrench because we’ve learned the hard way about overtightening. Maybe a bolt snapped off in an engine block, or a wheel stud sheared under too much grunt. Overtightening is a rookie mistake, and a pricey one at that.
So, you invest in a torque wrench to get it right on the tightening side. That’s its job, plain and simple: apply a specific amount of rotational force.
But then the question pops up when you’re trying to undo something that’s really stuck. You look at that calibrated bar or click mechanism and think, “Can I use a torque wrench to loosen a screw?” It feels like it should work, right? It’s still a wrench, after all.
The gut feeling is that if it can apply a precise amount of force to tighten, it should be able to apply force to loosen. It’s a bit like asking if you can use a hammer to unscrew a nail. Technically, you might get it out, but that’s not what the hammer was designed for, and you’re likely to do more damage than good. The same logic applies here, though the consequences might be less dramatic than smashing your thumb.
My own experience with this started when I was rebuilding a classic motorcycle. Everything had to be perfect, and every fastener needed to be torqued to spec.
I spent hours meticulously tightening bolts. Then came reassembly. One particular exhaust header bolt felt like it was welded in place. I tried my regular socket wrench, a breaker bar – nothing budged it.
My eyes landed on my click-type torque wrench. It has a decent range, and I knew I could get a good grip on it. The temptation was enormous.
I pictured myself applying just enough force to break it loose without damaging anything. It felt logical, but also… wrong.
I’d read enough to know torque wrenches are sensitive instruments, and I didn’t want to ruin the calibration for a few extra foot-pounds of loosening force.
So, the short answer, the one that often gets buried under layers of technical jargon, is: yes, you can, but it’s generally a bad idea and here’s why you should think twice. It comes down to precision versus brute force, and the internal mechanisms of these tools.
How Torque Wrenches Actually Work (and Why It Matters for Loosening)
A torque wrench isn’t just a fancy lever. It’s a precision instrument designed to measure and apply a specific amount of rotational force, known as torque. There are a few main types, but the most common ones you’ll find in a DIYer’s toolbox are click-type and beam-type. A click-type torque wrench has an internal spring-loaded mechanism that ‘clicks’ audibly and tactilely when you reach the set torque value. You set your desired torque, apply force, and when it clicks, you stop. Simple, right? (See Also: Do Deck Mate Screws Need A Pilot Hole )
Beam-type wrenches have a pointer that moves along a calibrated scale. As you apply force, the pointer indicates the current torque. You stop when the pointer reaches your desired setting. Both are designed to measure applied torque during the tightening process. They help prevent overtightening, which can strip threads, break bolts, or damage components, especially in important applications like engine assembly or wheel mounting.
Now, let’s talk about loosening. When you’re loosening a fastener, you’re applying torque in the opposite direction. The problem with using a torque wrench for loosening, especially a click-type, is that you’re basically subjecting its delicate internal mechanism to forces it wasn’t designed to handle or measure. The ‘breakaway torque’ – the force required to initially loosen a fastener – is often significantly higher than the torque used to tighten it. This is due to factors like thread friction, corrosion, thread locker, or even just being overtightened previously.
When you apply that higher force, you can potentially damage the internal spring and mechanism of the torque wrench. This can throw off its calibration. If the calibration is off, it won’t accurately measure the torque when you use it for tightening again. This is a real bummer. I once tried to loosen a seized brake caliper bolt with my click-type wrench, figuring I’d just be gentle. It didn’t click, but I felt a weird ‘give’ that wasn’t right. Later, when I tried to torque a wheel nut, the wrench clicked way too early. Cost me about $180 for a new one. It wasn’t worth the risk.
Think of it this way: a doctor’s scale is calibrated to measure your weight accurately. You wouldn’t use it to try and lift a car, even if it registered some force. You’d break it and wouldn’t trust its weight readings anymore. A torque wrench is similar. It’s calibrated for a specific range and direction of measurement.
When ‘can I?’ Meets ‘should I?’: Practical Scenarios
So, while the technical answer to “can I use a torque wrench to loosen a screw?” leans towards ‘yes, with caveats,’ the practical answer is usually ‘no.’ However, there are always exceptions, and understanding them can save you a headache, or at least help you make an informed decision. The biggest factor is the type of torque wrench and the nature of the fastener.
Beam-Type Wrenches for Loosening
Beam-type torque wrenches are generally more forgiving when it comes to loosening. Because they don’t have the sensitive click mechanism, they’re less likely to be damaged by a higher breakaway torque. You simply watch the needle on the scale. If the needle goes beyond the maximum range of your wrench, you know you’re applying too much force for the wrench to accurately read. You can still use it to get a feel for the resistance and apply force gradually. However, even with a beam wrench, you’re not getting an accurate reading of the breakaway torque itself. You’re just using it as a more controlled lever.
Click-Type Wrenches: The Big No-No
For click-type torque wrenches, the consensus among mechanics and tool manufacturers is a resounding ‘no.’ As mentioned, the internal mechanism is designed for the precise application of torque during tightening. Exposing it to higher, unmeasured forces during loosening can compromise its accuracy. If you absolutely must try to loosen something with a click-type wrench, do so very cautiously and be prepared for potential damage. Some people advocate for setting the torque wrench to its highest setting and using it very gingerly, but this is still risky.
What About ‘breakaway Torque’ Specs?
Some higher-end torque wrenches will actually list a ‘breakaway torque’ rating. This is the maximum torque the wrench can safely be used to loosen. It’s usually a bit higher than the maximum tightening torque. If your torque wrench has this specification and you’re within that range, you might be okay. However, for most standard DIY torque wrenches, this specification isn’t provided, and it’s best to assume it’s not designed for loosening.
My personal rule of thumb: If the fastener is just a bit tight, but not seized, and I can’t get it with a standard ratchet, I might consider using a beam-type wrench if that’s all I have. But for anything truly stuck, or with a click-type wrench, I’ll reach for a dedicated breaker bar or impact wrench first.
The Right Tool for the Job: What Else Can You Use?
If your torque wrench isn’t the ideal tool for loosening stubborn fasteners, what is? Fortunately, the world of tools is broad, and there are several options specifically designed for applying significant force to break fasteners loose. This is where you put the precision tool away and grab something built for a bit of a fight.
Breaker Bars: The Go-to Solution
A breaker bar is basically a long, sturdy metal bar with a socket drive head. It doesn’t have a ratcheting mechanism or any measurement capabilities. Its sole purpose is to provide use. The long handle allows you to apply a lot of torque with less physical effort. They are built to withstand high forces, far exceeding the safe limits of a torque wrench. They are also relatively inexpensive, making them a worthwhile addition to any toolbox. I have a 24-inch breaker bar that’s saved my bacon more times than I can count. It’s not pretty, but it works.
Impact Wrenches: For Seriously Stuck Fasteners
For fasteners that are truly seized, rusted, or over-torqued, an impact wrench is often the best solution. Whether it’s pneumatic (air-powered) or electric, an impact wrench delivers rapid bursts of rotational force (impacts) combined with torque. This hammering action can break the bond of rust or thread locker that’s holding a fastener in place. They come in various sizes, from small 3/8-inch drive models for general automotive work to larger 1/2-inch or even 3/4-inch drive units for heavy-duty applications. Using an impact wrench requires impact-rated sockets, which are made of a tougher material to withstand the hammering action. (See Also: Do Nvme Drives Come With Screws )
I’ve found that sometimes, even with a breaker bar, a bolt just won’t budge. That’s when I pull out my electric impact wrench. It feels like cheating, but it’s incredibly effective. You just have to be careful not to overdo it and strip the threads, especially on softer metals. A quick burst is usually all you need.
Penetrating Oil and Heat
Before you even reach for a tool, especially for rusted fasteners, consider using a penetrating oil. Products like PB Blaster or Kroil are designed to seep into the threads and break down rust and corrosion. Let it sit for a while – sometimes hours, or even overnight for really stubborn cases. Gentle tapping with a hammer on the head of the bolt can also help the oil penetrate. In extreme cases, a bit of heat from a propane torch can expand the surrounding metal, helping to break the bond. Just be mindful of what you’re heating and what’s nearby!
Here’s a quick rundown of my preferred methods:
| Problem | Recommended Tool/Method | Why it Works | My Verdict |
|---|---|---|---|
| Slightly tight fastener | Standard ratchet or breaker bar | Provides good use and control | Start here. Always the first step. |
| Moderately tight/stuck fastener | Breaker bar + penetrating oil | Increased use to break the bond, oil aids release | Reliable workhorse for most situations. |
| Severely seized/rusted fastener | Impact wrench + impact sockets + penetrating oil/heat | Rapid impacts break the bond; heat expands metal | The nuclear option, but often necessary. |
| Torque-sensitive fastener needing release | Beam-type torque wrench (used carefully) | Measures force, less likely to damage than click-type | Only if you absolutely MUST and have no other option. |
| Anything needing precise tightening | Calibrated torque wrench (click or beam) | Makes sure correct torque is applied | This is what they’re made for. Don’t mess it up. |
Common Mistakes When Using (or Misusing) Torque Wrenches
People make a lot of mistakes with torque wrenches, and not all of them are about trying to loosen a bolt. Some of these errors can be just as damaging to your tools or your project. Understanding these pitfalls can save you time, money, and frustration.
Setting the Torque Wrench Incorrectly
This is perhaps the most common mistake. People forget to set the torque wrench to zero after use, or they misread the settings. For click-type wrenches, make sure you’re setting the correct value. Many have a primary scale and a secondary vernier scale for finer adjustments. Not reading the manual or not understanding how to set it can lead to over or under-torquing. I’ve seen guys crank down on a bolt, thinking they were at 50 ft-lbs when they were actually at 75 ft-lbs because they didn’t properly align the vernier scale.
Using a Torque Wrench as a Breaker Bar
We’ve covered this extensively, but it bears repeating. This is the cardinal sin of torque wrench usage. Trying to loosen a stubborn bolt with a click-type torque wrench is a fast track to calibration hell. The sudden, high force can bend the internal spring or damage the mechanism. Even with a beam-type, while less prone to damage, you’re not getting an accurate reading and you risk applying excessive force.
Not Using the Right Socket Size
This might seem obvious, but I’ve seen it happen. Using a socket that’s slightly too large or too small can round off the corners of a bolt head or nut. This makes it incredibly difficult to get a good grip with any wrench, including a torque wrench, and can lead to stripped fasteners. Always use a snug-fitting socket. For hex bolts, make sure you’re using a 6-point socket, not a 12-point, as it offers better grip and is less likely to slip.
Applying Torque Too Quickly or Jerkily
Torque wrenches, especially click-type ones, are designed for a smooth, steady application of force. Jerking the wrench can cause you to overshoot the target torque before the wrench has a chance to register it properly, or it can cause the click mechanism to engage prematurely or inaccurately. For beam-type wrenches, a jerky motion makes it hard to read the precise point at which the needle stops.
Not Calibrating Regularly
Tools get dropped, banged around, and used. Even with careful use, torque wrenches can lose their calibration over time. Most manufacturers recommend calibration every 6-12 months, depending on usage. If you drop your torque wrench, or if it feels ‘off,’ get it recalibrated or tested. Using an uncalibrated torque wrench is almost as bad as not using one at all, as you’re relying on inaccurate data. Many auto shops and tool repair services offer calibration services. It’s a small price to pay for accuracy.
Storing a Click-Type Wrench on a Set Torque
This is a big one for click-type wrenches. When not in use, you should always set the torque wrench to its lowest setting or zero. Leaving the spring compressed puts a constant strain on it, which can lead to it losing its accuracy over time. It’s a simple habit that can significantly extend the life and reliability of your tool.
When Is It Okay to Use a Torque Wrench for Loosening?
Okay, I know I’ve been pretty firm about not using torque wrenches for loosening. But are there any situations where it’s not a catastrophic error? Yes, but they are few and far between, and require a good understanding of your tool and the situation. The primary consideration is the type of torque wrench and the expected breakaway torque.
Low-Torque Applications and Beam Wrenches
If you’re dealing with a very low-torque fastener (think small electronics, perhaps bike components where specs are in Newton-meters, not foot-pounds) and you have a beam-type torque wrench that can accurately read in that lower range, you might get away with it. You’re still not getting a precise breakaway torque measurement, but you’re using the tool to apply controlled force rather than brute force. For example, if a spec is 5 Nm and you’re trying to loosen something that was likely torqued to exactly 5 Nm, and you’re using a beam wrench, the risk is minimal. However, even here, a small, dedicated driver or a very careful application of a standard driver is often safer. (See Also: Does Showing Screw Driver Into The Ignition )
You Have Absolutely No Other Option (and Accept the Risk)
Sometimes, you’re in a bind. You’re working on a project, it’s late, stores are closed, and the only tool that might work is your torque wrench. In such a dire situation, you might decide to risk it. If you’re using a click-type wrench, set it to its highest setting. Apply force very gradually and smoothly. Listen and feel for any unusual noises or give. If it feels wrong, stop immediately. Be prepared for the possibility that the wrench may no longer be accurate for tightening afterward. This is a last resort, and you should immediately plan to get your wrench checked or replaced if you go this route.
Understanding the Difference Between Torque and Force
It’s also important to remember that torque is a measure of rotational force. When loosening, you’re overcoming static friction and potentially any thread locker or corrosion. The force you apply is often much higher than the tightening torque. A torque wrench is designed to measure the force applied during tightening, up to its rated capacity. It’s not designed to measure or withstand the potentially much higher, instantaneous force required to break a fastener loose.
I recall a situation where I was assembling a model airplane. The instructions called for a very specific, tiny torque value. When it came time to disassemble a section months later, one of the tiny screws was a bit stubborn. I used a small, precision beam-type driver. It wasn’t technically a torque wrench, but it had a scale. I was able to apply just enough twisting force to get it out without stripping the threads or damaging the plastic. That’s the kind of nuanced application where you might get away with it, but it’s a far cry from loosening a seized lug nut.
Can a Torque Wrench Be Used for Anything Other Than Tightening?
While primarily designed for tightening, some beam-type torque wrenches can be used for loosening with caution, as they are less prone to damage from higher forces than click-type wrenches. However, their accuracy for measuring breakaway torque is limited, and dedicated tools like breaker bars are generally preferred for loosening stubborn fasteners.
Will Using a Torque Wrench to Loosen Damage It?
Yes, especially if it’s a click-type torque wrench. The internal mechanism is not designed to withstand the often higher breakaway torque needed to loosen seized fasteners. This can throw off calibration or permanently damage the wrench.
What’s the Difference Between Torque and Breakaway Torque?
Torque is the rotational force applied to tighten a fastener to a specific specification. Breakaway torque is the force required to initially loosen a fastener that has already been tightened, and it’s often significantly higher than the tightening torque due to friction, corrosion, or thread locker.
Is It Safe to Use a Torque Wrench on a Rusted Bolt?
No, it is generally not safe or advisable to use a torque wrench on a rusted bolt, especially a click-type. The rust increases the breakaway torque significantly, risking damage to the torque wrench. It’s better to use penetrating oil, heat, and a breaker bar or impact wrench for rusted fasteners.
What Should I Do If I Accidentally Used My Torque Wrench to Loosen a Bolt?
If you’ve accidentally used your torque wrench to loosen a bolt, especially a click-type, it’s highly recommended to have it recalibrated by a professional or consider replacing it. The accuracy for future tightening tasks may be compromised.
Conclusion
So, after all that, can I use a torque wrench to loosen a screw? The blunt, honest answer is: you shouldn’t, especially if it’s a click-type. You bought it for precision on the tightening side, not for brute force on the loosening end. Think of it like a surgeon’s scalpel – you wouldn’t use it to pry open a stubborn jar. It’s delicate and meant for specific, controlled tasks.
If you’ve got a fastener that’s really stuck, put the torque wrench back on the shelf. Grab a breaker bar, some penetrating oil, maybe even your impact wrench if you’re feeling adventurous. These tools are built for that kind of work, and they won’t leave you with a costly, inaccurate torque wrench as a souvenir of your efforts.
Next time you’re faced with a seized bolt, remember this. Save your torque wrench for what it does best: making sure your bolts are just right, not too tight and not too loose. It’s about respecting the tool and the job it’s designed for. Your wallet will thank you.
