Both breaker bars and torque wrenches are important tools that are commonly used when working on vehicles or machinery. However, they serve different purposes and have key differences that make each one better suited for certain tasks.
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What is a Breaker Bar?
A breaker bar, also known as a torque bar, cheater bar, or lever bar, is a long non-ratcheting metal bar that is used to provide additional leverage when loosening or tightening stubborn fasteners. The key features of a breaker bar are:
- Typically made of solid steel or chromoly steel for strength
- Available in varying lengths from 12 inches to 36 inches
- Has a square drive socket on one end to fit sockets
- Does not ratchet or pivot – simply acts as a lever
- Often has a hexagonal or rounded handle for grip
The main purpose of using a breaker bar is to generate very high amounts of torque. By using the lever principle, a breaker bar can produce much more torque than you could generate just using a standard socket wrench or ratchet. The longer the breaker bar, the more torque it can generate. This makes breaker bars ideal for loosening or initially tightening very stubborn fasteners that a ratchet cannot loosen on its own.
What is a Torque Wrench?
A torque wrench is a more specialized tool that allows you to precisely measure and control the amount of torque being applied to a fastener. The key features of a torque wrench are:
- Available in different drive sizes (1/4″, 3/8″, 1/2″ etc)
- Measures applied torque via an internal spring mechanism
- Adjustable torque setting to preset desired torque value
- Will “click” or slip when preset torque is reached
- Usually have a gauge to show current torque setting
- Come in different styles – beam, click, and dial types
The purpose of a torque wrench is to tighten or loosen bolts, nuts, and other fasteners to a specific, preset torque value. Properly torquing fasteners is critical to ensure parts are securely assembled without damage from overtightening. A torque wrench allows precision control over the tightness applied to each fastener based on its size and application.
Key Differences
While both are used when working with threaded fasteners, here are the main differences between breaker bars and torque wrenches:
| Category | Breaker Bar | Torque Wrench |
|---|---|---|
| Purpose | Generating maximum torque to loosen stuck fasteners | Tightening/loosening to a precise torque value |
| Torque Control | User judged – no measurement | Adjustable and measured torque settings |
| Length | Typically over 12 inches long | Short length for better control |
| Drive | Usually 1/2″ square drive | Available in multiple sizes |
| Usage | Starting stuck fasteners, initial tightening | Final tightening to spec |
As shown in the table, the main difference comes down to torque control. A breaker bar is solely used for generating maximum force, with no measured control. The user simply bears down until the fastener starts moving. A torque wrench is a precision tool for controlled tightening and loosening, with the exact torque values set for each application.
When to Use Each One
Due to their different purposes, breaker bars and torque wrenches are used in different stages when working with difficult fasteners:
- Use the breaker bar first to initially break loose a stuck fastener. The extra leverage can provide enough force to get it moving.
- Once broken loose, you can switch to a ratchet or socket wrench to start removing the fastener.
- For re-installation, do initial tightening with a ratchet until hand-tight.
- Then use the torque wrench to precisely tighten the fastener to its final spec torque.
The breaker bar helps initially overcome the fiction and corrosion locking down the fastener. The torque wrench provides precise control at the end to avoid over or under tightening. Using both tools in combination allows you to safely service fasteners.
Types of Torque Wrenches
There are a few common types of torque wrenches to be aware of:
Beam Style
- Most basic style
- Bar with handle and calibrated scale showing torque value
- pointer shows torque setting on scale
- Requires more skill and focus to use properly
Dial/Digital
- LCD or dial display shows realtime torque value
- User sets desired torque on digital/dial interface
- Does not require watching a scale while tightening
- Often higher cost than beam style
Click Type
- “Click” signals when preset torque is reached
- No need to watch display – audible click feedback
- Less user technique needed
- Most common style of torque wrench
There are also electronic and hydraulic torque wrench designs. But click types are the most prevalent due to their ease of use and lower cost than digital models.
Choosing the Right Size
Breaker bars and torque wrenches come in different drive sizes – typically 1/4″, 3/8″, and 1/2″ drives. The drive size dictates the size sockets that can be used.
- 1/4″ drive – used for smaller fasteners in electronics or precision applications. Common torque range is 25-100 ft-lbs.
- 3/8″ drive – used for general automotive sizes – common torque of 30-150 ft-lbs range.
- 1/2″ drive – used for heavy equipment, trucks, and large fasteners – high torque over 150 ft-lbs.
Make sure to select breaker bars and torque wrenches in a drive size suitable for your typical fastener sizes and torque requirements.
Safety Tips
When using breaker bars and torque wrenches, keep these safety tips in mind:
- Use appropriate sockets that match fastener size to avoid rounding.
- Keep tools in good condition – repair/replace if damaged.
- Ensure you have stable footing when applying torque.
- Beware of extension “snap back” if fastener breaks free suddenly.
- Double check torque wrench calibration periodically.
- Always pull torque wrench smoothly when tightening to specified torque.
Applying high torque can be dangerous. Following safe practices will help avoid injuries and damage when using these tools.
Conclusion
In summary:
- Breaker bars generate high torque for initial loosening of stuck fasteners.
- Torque wrenches allow precise tightening and loosening to a pre-set torque value.
- Use a breaker bar first to break free stuck bolts, then switch to a torque wrench to finish tightening to the proper final torque.
- There are beam, dial/digital, and click style torque wrenches to suit different needs.
- Choose the drive size based on your fastener sizes and typical torque requirements.
- Always use proper safety practices when generating high torque forces.
Understanding the key differences between breaker bars and torque wrenches, and when to use each, will allow you to safely service fasteners and avoid damage. Be sure to use the right tool for the job!