Breaker bars are a staple in most mechanical workshops. What are they, and what are they used for?
This article unpacks the practicalities of breaker bars and their uses.
What is a Breaker Bar?
A breaker bar is a socket drive with a long handle that is used to break loose frozen fasteners. Breaker bars are non-ratcheting and the drive head which is usually ½ inch square in size may swivel. The longer handle of the tool delivers greater leverage to loosen tight nuts and bolts.
A breaker bar is the socket wrench’s bigger cousin. This tool connects to nuts and bolts in the same way that a socket wrench does, but its handle is far longer.
What is a Breaker Bar Used for?
Breaker bars are used to loosen tight, frozen, and rusted bolts and nuts. One of the most common applications of a breaker bar is to loosen the frozen lug nut of your car tires.
When replacing the tire, you may find that the lug nut is rusted or over-tightened (always use a torque wrench to tighten lug nuts). If you have an impact wrench or high torque impact driver, removing the stubborn lug nut is an easy job. However, managing this using a standard socket wrench is difficult. Usually, it results in straining your back or shearing off the bolt.
Similar to a crowbar or pry bar, breaker bars offer greater leverage and lightening the operator’s load. Here, you can easily loosen stubborn bolts without straining your back or hands.
Breaker Bar Sizes
Breaker bars come in various sizes and are typically specified according to their length and drive size.
The length of a breaker bar is measured from the socket tip handle end while the socket is fully extended. When in use, the swivel drive would typically be at 90° with the handle, thus shortening the breaker bar’s effective length.
Standard lengths for breaker bars are 18 inches (45 cm), 24 inches (61 cm), and 30 inches (76 cm), although they can be as long as 40 inches (100 cm). Of these, the 24-inches one is the most common.
While longer breaker bars offer greater torque and thus a greater ability to free locked nuts, this is not always better. The high torque offered by longer handles could produce so much force that the bolt shears off instead of loosening. For perspective, a 40-inch breaker bar can produce 7 psi (48 kPa) of torque. Most bolts will come loose with that amount of torque. If they don’t, you may need to cut them off instead.
The staggering amount of torque created by the 40-inch breaker bar is ideal for loosening lug nuts on trucks and other large vehicles. These typically have rims larger than 20 inches (50 cm), thus offering adequate maneuvering room for the longer handle.
Longer handles also don’t fit into tight spaces, such as wheel wells. When choosing a breaker bar, bear the limitations of the intended application in mind.
The breaker bar usually comes with a square drive head. The drive size is the distance between the two flat sides expressed in inches or nearest millimeter sizes.
Breaker bars typically have one of four drive sizes:
- ¾ inch (19 mm)
- ½ inch (13 mm)
- ⅜ inch (10mm), and
- ¼ inch (6mm)
The most common of these are the ½ inch and ⅜ inch ones since they fit the most commonly used larger nuts, such as lug nuts. Long-handles breaker bars, such as the ¾ inch ones, typically use the larger drive sizes, such as the ¾ inch ones. In contrast, shorter breaker bars typically use the ¼ inch drives.
Socket sizes can be adapted using drive size adaptors, although this should be done with caution. The adapter adds a weak point to the tool. If too much torque is applied, it could snap or be damaged under the load. This could also damage the breaker bar’s socket, and the nut being loosened, both of which will make your job even more difficult.
You could also use extenders when using a breaker bar in hard-to-reach spaces. As with the socket size adapters, this should be done with caution since it adds a layer of weakness to the tool.
What Size Breaker Bar for Lug Nuts?
The 18-inch breaker bar with a ½ inch drive is the most commonly used tool for loosening lug nuts on most makes of cars. Here, the breaker bar offers sufficient torque to loosen the nuts, but not so much that it will shear off the bolt.
How to Use a Breaker Bar?
Using a breaker bar can be uncomfortable for the uninitiated. Here are the steps to use a breaker bar effectively to loosen stubborn nuts and bolts.
1. Wear Gloves
The handle tends to be rough and can hurt the palm of your hand, especially if you’re not using one of the ergonomic models with molded handles. So, it is good to wear gloves when using a breaker bar.
2. Wear Safety Glasses
It is also possible that the bolt being loosened could shear off, sending splinters flying. For this reason, it is good practice to wear safety glasses when working with frozen fasteners.
3. Inspect and Clean
Before using the breaker bar, inspect the nut or bolt to be loosened. If it is heavily corroded or dirty, is it good practice to clean off some debris from the surface. This will allow the drive greater purchase on the nut or bolt, minimizing the risk of slipping and consequent injury.
4. Attach the Socket
Next, place the drive securely into the correct size socket. Keep the handle as close to 90° to the drive as possible.
5. Breaker Bar Operation
Place one hand behind the drive and the other on the handle. With your feet firmly on the ground, shoulder-width apart, turn the handle anti-clockwise to loosen the bolt. If possible, ensure that the socket is positioned such that you can press down on the handle since this is far easier than pulling it upwards.
Work carefully, and try to increase the pressure on the handle slowly, not in one forceful movement. This minimizes the instantaneous force on the bolt and so decreases the risk of shearing it off.
The breaker bar has no ratchet mechanism. So, you should reposition the handle to the starting point once you’ve reached the end of the available range of motion. Repeat the process until the nut is loosened.Tip Apply a penetrating oil such as WD-40 into the threads of stubborn nuts and bolts with excessive rust. Allow the oil to penetrate into the threads before you use the breaker bar.
What Can I Use If I Don’t Have a Breaker Bar?
Breaker bars are effective at loosening tight bolts and nuts because they increase the available torque with their long handles. So, if you don’t have a breaker bar, the same principle can be applied by extending the handle length on your standard socket wrench.
If you don’t have a breaker bar, use a cheater bar with a socket wrench. Here, you could place a piece of steel pipe, or pipe made from another metal, over the socket handle to extend it and use it as a breaker bar.
Some caution is advised, though, since standard socket wrenches aren’t designed to handle the increased torque the same way that breaker bars are. Ensure that you don’t apply too much force to your socket wrench since it could easily break under excess pressure.
If you have time to spare, it may be a good idea to apply some penetrating oil to the stubborn nut or bolt. If you leave that to do its job for a few hours, you could potentially loosen it without resorting to a cheater bar.
Another alternative to the breaker bar is to use a power tool such as an impact wrench to change your car tire.
Can You Use Impact Sockets with a Breaker Bar?
Impact sockets will work fine with breaker bars. However, impact sockets are more expensive than chrome sockets and sometimes the thicker walls may prevent them from going in tight spots.Caution: If you apply excessive force on the lever when dealing with frozen fasteners beyond recovery, usually either the fastener or the chrome socket will break. But if you use an impact socket instead of a chrome socket you have the risk of cracking the breaker bar which can be very fatal.