Torque tools are widely used in industry and machinery and are very important. Therefore, in this article, TorcStark will discuss two types of torque tools, torque multipliers and torque wrenches. By comparing their advantages and disadvantages, we can help you better choose the right tool.

Now, let’s get started!

I. Features and advantages of torque wrenches and torque multipliers

1. Features and advantages of torque wrench

(1) Definition:

A torque wrench is a hand-held tool that accurately controls torque. It is also called a torque adjustable wrench and is a type of wrench. It can tighten the nut with a specific torque and is mostly a socket wrench with a specific mechanical structure. When the tightness of screws and bolts is critical, using a torque wrench allows the operator to apply specific torque values.

(2) Working principle:

The torque wrench has a torque release structure inside, composed of three parts: a pressure spring, a torque release joint, and a torque ejector rod.

When using it, you must first set the torque value on the torque wrench. Here, a spring is placed on the ejector rod to apply pressure on the torque release joint, lock the torque wrench, and start tightening the bolt.

When the bolt reaches the torque value, the torque used at this time is greater than the pressure of the spring, which will produce an instant disconnection effect.

When an instant disengagement occurs, the metal shell of the wrench will make a “click” sound, or the wrench connection will bend at a slight angle, thus reminding and confirming that the torque value has been reached, which means that it has been tightened and no additional force is needed.

(3) Accuracy:

Torque wrenches have the advantages of high precision, low failure rate, long life, control of torque and angle, and a variety of torque options. Most torque wrenches, regardless of type, specify a certain range of expected accuracy; typically ±2-4% of 20%-100% of full scale for a particular wrench. In terms of reliability, torque wrenches typically require maintenance and calibration after 100k tightenings or one year.

(4) Scope of application

Torque wrenches are critical tools in the automotive repair industry. It is used to install or remove the bolts and nuts of the car, ensuring that they are tightened correctly to avoid loosening or damage.

In aircraft manufacturing and repair, torque wrenches are used to tighten critical components such as aircraft engines and wing connections.

In the railway industry, torque wrenches are used to tighten rails, connect rail components, etc. to ensure the stability and safety of the railway.

In the food and pharmaceutical industries, torque wrenches are used to install and maintain production equipment to ensure the normal operation of the production line.

2. Features and advantages of torque multiplier

(1) Definition:

A torque multiplier is a tool that increases output torque through a mechanical device. It increases torque for the operator. Since the output power does not exceed the input power, the output rotation number is lower than the input rotation number. Torque multipliers generally achieve torque multiplication through planetary gears, generally amplifying 5 times to 125 times, and the maximum output torque can reach about 50,000 Nm.

(2) Working principle

The torque multiplier is composed of a circular or planetary gear combination in different combination levels to drive the gear rotation and output. Each level of gear brings torque amplification.

In a planetary gear system, torque is input and output via the sun gear. The rotation is driven by three or four planetary gears combined with a central gear.

The circumferential gears within the multiplier housing are engaged with the surrounding inner planetary gears but rotate in the opposite direction relative to the rotation of the inner planetary gears.

From the outside, the torque multiplier is composed of an input square head part, an anti-rebound lock, a multiplier body part, a reaction arm part, and an adapter sleeve part.

The reaction arm part extends out of the body to a certain length, which can prevent the housing integrated with the circumferential gear from rotating and cause the planetary gear to rotate around the center gear to drive the driving square head to rotate, thereby outputting torque.

(3) Powerful functions:

Precision planetary gear torque increasing system, high torque accuracy, and small error.

The torque multiplier is very sturdy and can be used continuously and intensively.

Especially suitable for heavy industries such as petroleum, chemical industry, energy, and so on.

It can multiply the torque and is mostly used for disassembling and assembling large screws and high-precision bolts. Equipped with overload protection, it achieves the accuracy and safety of outputting 20 times the torque. For example: in the tightening and disassembly of pipe flange bolts of generators, turbines, and chemical plants in power plants, the torque is multiplied through planetary gears. Generally, the amplification is 5 to 125 times, and the maximum output torque can reach about 50,000 Nm.

Using extension poles can be dangerous. Use a torque multiplier to reduce extension length and user effort by amplifying the torque by 5, 25, or 125.

Torque multipliers are ideal for use in tight spaces where longer extension rods cannot be used.

(4) Scope of application:

In situations where high-torque bolts need to be tightened, a conventional torque wrench may not provide enough force. A torque multiplier can counter this by increasing leverage.

In some tight spaces or hard-to-reach areas, it can be very difficult to use a conventional torque wrench, and a torque multiplier can solve this problem through the lever principle.

When working with high-strength materials, more torque may be required to ensure safe and secure fasteners.

II Comparative Analysis: Torque Wrench vs Torque multiplier

(1) Accuracy comparison

There is no big difference in accuracy between torque wrenches and torque multipliers, both can output torque values accurately.

However, torque wrenches are more accurate and can provide more accurate torque readings. And can perform precise torque adjustment.

The accuracy of torque multipliers may be slightly lower because they usually amplify torque through the lever principle, and there is a certain transmission error.

(2) Torque range comparison

Generally speaking, the torque range of a torque wrench is relatively narrow, usually between a few Newton meters (Nm) and a few hundred Newton meters.

Torque multipliers typically provide a wider range of torque output, which can range from a few hundred Newton meters to thousands of Newton meters.

(3) Similarities and differences in applicable scenarios

Torque wrenches are suitable for occasions that require precise torque control, such as automobile maintenance, mechanical assembly, etc.

Torque multipliers are mainly used in situations where an extremely large torque is required, such as construction machinery, heavy equipment, and other fields. A torque multiplier can also provide greater assistance in tight spaces or hard-to-reach areas.

(4) Cost-benefit comparison

Generally speaking, torque wrenches are less expensive than torque multipliers, especially for general repair and assembly tasks. And torque multipliers usually add significant cost. This is because they offer greater torque output and are typically used in more demanding industrial applications.


Generally speaking, most bolt tightening can be completed using a torque wrench in daily life or industrial production. Moreover, the torque wrench has high precision, low cost, and wide application range, making it the best choice in the general field.

When your engineering project requires extra-large torque to fasten bolts or the space is very small, the torque multiplier can better help you complete the work.

Therefore, it is recommended that you choose appropriate tools according to the working conditions, rather than blindly pursuing brand and accuracy.