I always recommend using the right tool for the job. And, if you are trying trying to use a torque wrench as a breaker bar, or even to break bolts, then you’re not using the right tool.
A torque wrench should not be used as a breaker bar because doing so will, at best, ruin the accuracy of the tool or worse, destroy it completely.
Still, let’s investigate what would happen if you abuse a torque wrench or use it for things other than its intended purpose.
How Does A Torque Wrench Work?
If you compare a torque wrench to a ratchet, you’ll see they have a lot in common. They both use interchangeable sockets and have an internal ratcheting mechanism that controls the turning direction. A torque wrench, however, is designed to apply a specific amount of torque to a fastener, where a ratchet is not.
To accomplish this, a torque wrench uses a number of components located inside the barrel and handle. The components include a ratchet assembly, pivot pin, pawl and cam assembly, torque spring, and adjustment screw among other small components.
Here is how it goes together, starting from the bottom: the adjustment screw is inserted into the barrel and the handle installed. From the top, the torque spring is inserted into the barrel, followed by the pawl and cam assembly. Finally, the ratchet assembly is inserted and held in place by a pivot pin.
The adjustment screw is turned with the handle and increases or decreases the amount of tension on the torque spring. The spring, in turn, pushes against the pawl and cam assembly making it more or less difficult for the ratchet assembly to cam out. There is an audible click when it does, letting you know your desired torque level is achieved.
Other Torque Wrench Types
The click-type torque wrench I described above is by far the most common, but there are three more common types you may run across. None of which should be used as a breaker bar.
Beam-Type Torque Wrench
The first variation is called a beam-type torque wrench and it is probably the oldest and simplest version of the tool. It features two parallel beams. One beam has the handle and reading plate and the other, called a pointer beam, has a small pointer at one end. The beams are attached together at the end opposite the handle. This connection point also has an anvil, to which sockets are attached.
When torque is applied, the first beam deflects while the pointer beam does not. The torque level can be measured on the reading plate as indicated by the pointer beam. Simply turn the handle until the desired torque level is achieved.
Dial-type Torque Wrench
The second type, called a dial-type torque wrench, operates in the same way as a beam-type torque wrench. It also uses two beam and relies on deflection to measure torque. Instead of a pointer and reading plate, however, it uses a dial indicator to read the torque level.
Because they are easier to read and more accurate, a dial-type torque wrench is generally preferred over a beam-type. Some may offer additional benefits like a memory pointer to measure maximum torque or a visual or audible indicator.
Digital Torque Wrench
Ease of use and accuracy are the hallmarks of a digital torque wrench. Since it doesn’t have a ton of moving parts, it’s also strong.
Unlike other torque wrench types, a digital torque wrench does not use any mechanical means of measuring torque. Instead it relies on a small device called a strain gauge.
When torque is applied to a fastener the strain gauge becomes deformed causing changes in electrical resistance. This change is measured, interpreted, and sent to the digital display on the torque wrench to be read.
A digital torque wrench is very accurate and many pack features above and beyond what other torque wrenches offer.
What Is A Breaker Bar Used For?
If you have to remove really stuck-on fasteners, then a breaker bar is one of your best options. It’s a simple, robust tool made specifically for the task.
Like a torque wrench and ratchet, a breaker bar uses interchangeable sockets that match the size and shape of each fastener. Instead of a ratcheting mechanism, however, it uses a solid head that is attached to the breaker bar handle with a pin or screw. Other than that, there are no moving parts.
To use a breaker bar, simply attach an appropriately sized socket, put it on the fastener, and turn. To avoid reversing your progress, you will have to remove the breaker bar from the fastener each time you turn it.
Since they are so robust, a breaker bar doesn’t have many weak spots. The most common failure you see is to the head, which is easily replaced. The forks, to which the head is attach, can also spread if significant torque is applied. This, likewise, is easy to fix by bending them back in place.
Why Can’t A Torque Wrench Be Used As A Breaker Bar?
Though a torque wrench is strong, it is still a precision instrument. Using it for tasks outside what it was designed for or beyond its torque limit will damage or destroy it. There are three ways I’ve seen this play out.
Damaged Pivot Pin
The pivot pin is a crucial component of a torque wrench and also one of its weakest. If too much torque is applied, the pin can bend or break. When this happens, the torque wrench becomes inaccurate, or, in the case of a broken pin, may not function at all. It is from this point, that torque is accurately measured so it needs to be in good working order.
Luckily, if damaged, the pivot pin can be easily replaced. However, in rare occasions the hole the pivot pin goes into can become so damaged that a repair is not feasible.
Misaligned Pawl And Cam Assembly
A torque wrench relies on the pawl and cam assembly to tell you when the desired torque level is met. When excessive torque is applied, the ratchet assembly can become misaligned with the pawl and cam assembly, rendering the torque wrench inoperable. Beyond that, damage can occur to these components, which will need to be replaced.
If this happens, the torque wrench has to be taken apart to realign the assembly or replace parts. Once reassembled, it will need to be recalibrated.
Damaged Torque Spring
To measure torque accurately, a torque wrench relies on constant, consistent pressure from the torque spring. Through normal use, two things will eventually happen to the torque spring. First, it will loosen up and the spring rate will change. Second, the spring will develop a memory. In both cases, the torque wrench will need to be recalibrated to restore accuracy.
If abused, this wear will occur at an accelerated rate and require more frequent servicing. In rare cases the spring can actually break and need to be replaced.
Summary
The answer to the question “can a torque wrench be used as a breaker bar” is a resounding no. It’s a precision instrument that requires exact calibration to maintain accuracy. When you use it for things it was never meant to do you risk ruining this accuracy or possible destruction.
A breaker bar is among the best tools for breaking bolts. That’s what it was designed for, after all. Use the right tool because, in this instance, the risk is not worth the reward.
Do you have any questions about torque wrenches or breaker bars? Let me know in the comments below. And if you’d like to learn more about torque wrenches, check out our Torque Wrenches Category.
