How Do Torque Multipliers Work?

Worlifts is a proud distributer of Norbar Torque Tools, and a popular product in the range is the Norbar Torque Multiplier.

But how do they work?

If you’ve ever had to do something as mundane as change a car wheel, you’ll know that loosening the bolts can be difficult.

On standard cars, however, these bolts are not meant to be so tight that they cannot be removed by a competent person using a standard tyre bar.

Some garages make the job easier by using a “breaker bar”, sometimes called a “cheater bar”.

What these do is to extend the length of the tyre bar and this makes it easier to undo, or indeed tighten, the bolts.

Breaker bars work because the extended length allows the same amount of force, applied by the operator, to generate significantly more torque. In some cases, you can use a length of pipe to provide the same result, but this is frowned upon by the industry and could be dangerous.

Fitting tyres is one thing, tightening or loosening bolts on critical equipment is quite another, and breaker bars simply don’t give the amount of control needed to ensure safe operation.


Torque Multipliers

This is where torque multipliers come in.

They typically use epicyclic gearing. As WikiPedia puts it:

An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates to carry one gear, called the planet gear, around the other, called the sun gear. The planet and sun gears mesh so that their pitch circles roll without slip. A point on the pitch circle of the planet gear traces an epicycloid curve. In this simplified case, the sun gear is fixed and the planetary gear(s) roll around the sun gear.

epicyclic gearing as used in torque multipliers

In a torque multiplier, each of the stages of gearing multiplies the torque applied to the bolt.

For example, a torque multiplier with a ratio of 5:1 will result in an output at the shaft of five times the torque, but as energy can’t be created, it means the speed will be one fifth.

Of course, no gearing is 100% efficient, so Norbar tools are engineered to give a typical ratio of 5.45:1, giving a true multiplication factor of 5:1.

Torque Multipliers

Calculating Torque

As the torque on many applications is often critical, this means that there is no guesswork when it comes to tightening bolts. The amount of torque needed can be calculated with simple arithmetic rather than relying on graphs or complex formulae.

Norbar’s HandTorque range is one of the most comprehensive available, with standard products up to 47,000 N-m and specials up to 300,000 N-m. And where bolts are difficult to get to, there is also a wide range of nose extensions.

As a certified distributer of Norbar products, Worlifts is best placed to provide you with the information, products and training you need to ensure you get the right tool for the job.

We can also provide servicing and repair at our accredited service centre.

Give us a call today to see how we can help!

related Product Information

View Our Range?

Check out the torque multpliers range directly available from Worlifts.

If you are unable to find the ideal solution or require assistance then Worlifts team of in-house experts are able to assist. Send us a message via our contact form or call us on +44(0)121 460 1113


Need To Hire?

Check out the torque multipliers range directly available from our hire range.

If you are looking to hire then Worlifts offers an extensive range of Hydraulic Tools. Contact our in-house experts who will be happy to assist. Send us a message or call us on +44(0)121 460 1113