Cheater bar

Seabees use a cheater bar to secure a bulldozer

A cheater bar or cheater pipe is an improvised breaker bar made from a length of pipe and a wrench (spanner).

Primary use

Cheater bars are usually used to free screws, bolts, and other fasteners that are difficult to remove with a ratchet or wrench alone. Cheater bars are also commonly used to operate valves.

When the handle of a wrench or ratchet is inserted into a cheater bar, the additional distance makes it possible to generate the required torque with the same amount of force being applied. However, the work done is the same with or without the cheater bar because the torque and angle of rotation needed to accomplish a particular task does not change.

The cheater bar allows higher torque with the same force by:

$torque = radius \times force$

A cheater bar is sometimes called a pipe extension or an extension pipe.

Industrial safety problems

Problems in using such bars include:

1. If the component frees suddenly the worker can become a projectile that is propelled into whatever is in the "line-of-fire." This could (and has) resulted in falls, impacts, punctures, and other injuries.
2. The cheater bar itself can become part of a de-facto catapult with the worker in the line-of-fire.^[1]
3. If the over-torquing results in the failure of any of the items in the jury rig the fragments can injure workers in the line-of-fire.^[2]
4. The use of the cheater bar can result in component damage that can, in turn, harm workers.^[3]

Some organizations forbid their use. For example, NASA proscribes:

"Use the approved tool for the job. Makeshift arrangements such as the use of a screwdriver as a chisel, a pair of pliers as a wrench, a wrench as a hammer, or overloading a wrench by using a pipe extension (cheater bar) on the handle are not to be employed." ^[4] (emphasis added)

Notes

1. ^ DOE | Office of Health, Safety and Security | Corporate Safety Analysis
2. ^ Using cheater bars on hand tools
3. ^ Power Engineering - Valve Vigilance
4. ^ http://server-mpo.arc.nasa.gov/Services/Proc/ProcDocs/APG1700.1-R/Chap%2014.pdf