Torque is the rotational force applied to an object, such as a bolt or a nut, and the amount of torque used directly influences how securely it is tightened. Applying the correct amount of torque ensures that the bolt is neither too loose nor overtightened, helping to maintain structural integrity and prevent potential failures.
Gaining an understanding of how torque is measured can help engineers and operatives in manufacturing enhance their torque management. In the automotive, process and aerospace industries, torque management is essential to ensure safety, accuracy and compliance.
If you are trying to understand what units’ torque is measured in, you’ll quickly notice there isn’t just one answer. Different industries and regions use different systems, so several torque units are commonly used.
The most common units of torque you’ll come across are Newton-metres (N·m), pound-force feet (lbf·ft), inch-pounds (in·lb) and kilogram-centimetres (kgf·cm). Some are based on the metric system, others on imperial, which is where things can start to feel a bit inconsistent if you’re working across borders.
In practice, knowing what torque is measured in isn’t just a technical detail. It directly affects how accurately components are assembled, how safe they are in use and whether they meet required standards.
How is torque measured?
In most cases, it comes down to using tools that can apply a controlled amount of rotational force. The one most people are familiar with is the torque wrench. It’s designed to tighten a fastener to a set value, so you’re not relying on guesswork.
Tools such as torque wrenches and torque transducers are relied upon in many industries to ensure accuracy and precision. If a nut or a bolt is overtightened or loose, it could fail, leading to catastrophic circumstances.
For example, a nut or bolt failure in the automotive industry can cause mechanical failures or unsafe vehicle operation. In engineering and manufacturing processes, torque management can ensure product quality, safety, performance, and reduce the risk of structural issues. In high-demand environments such as these, reliable torque management is vital.
Across industries like automotive, aerospace and general manufacturing, accurate torque measurement isn’t optional. If the applied torque falls outside the required range, it can lead to failures that are expensive at best and dangerous at worst.
That’s why the correct use of torque measurement units matters just as much as the tools themselves.
Common torque units of measure
There’s no shortage of torque units, but a handful are used far more than others. Each one is based on the same principle, force applied over a distance, but expressed differently depending on the system.
The common units’ torque is measured in include:
- Newton-metres (N·m)
- Pound-force feet (lbf·ft)
- Inch-pounds (in·lb) also known as Pound-force inches (lbf·in)
- Kilogram-centimetres (kgf·cm)
Newton-metres (N·m)
Newton-metres (N·m) are the standard SI unit of torque, and in most cases, they’re what you’ll see used as the default. One Newton-metre is the force of one Newton applied at a distance of one metre from a pivot point.
Because it’s the global standard, this is the most widely used of all torque measurement units. You’ll find it in engineering specifications, technical documentation and most manufacturing environments.
Pound-force feet (lbf·ft)
Pound-force feet (lbf·ft) come from the imperial system and are still widely used in the United States. This torque unit of measure represents one pound of force applied over a distance of one foot.
If you’ve ever worked with US-based manuals or automotive data, you’ve probably seen this used regularly. It’s one of the main units of torque you’ll need to convert if you’re switching between systems.
Inch-pounds (in·lb)
Inch-pounds (in·lb) are essentially a smaller version of pound-force feet. They’re used when finer control is needed. They’re common in electronics, small components and assemblies when applying too much force could cause damage.
This measure is particularly useful in applications where even the smallest of adjustments can make a big difference.
Kilogram-centimetres (kgf·cm)
Kilogram-centimetres (kgf·cm) are used in some metric-based applications, especially in areas like robotics and mechanical systems. This unit measures the force of one kilogram acting over a distance of one centimetre. They’re not as widely used as Newton-metres, but they still appear often enough to be worth understanding, especially if you’re working across different regions or sectors.
How to convert torque units
At some point, you’ll almost certainly need to convert torque units. It’s a common part of working across different systems, especially when specifications, tools or suppliers don’t all use the same standard.
A lot of modern equipment can handle torque unit conversion for you, but it still helps to know what’s happening behind the scenes.
You can of course use our own Torque Calculator to convert the units of measurement, but the manual calculations for torque unit conversion are as follows:
Newton-metres to Pound-feet:
Multiply the torque value by 0.7376. For instance, 10 N·m = 7.38 lbf·ft.
Pound-feet to Inch-pounds:
Multiply the torque value by 12. For example, 5 lbf·ft = 60 in·lb.
Newton-metres to Inch-pounds:
Multiply the torque value by 8.8507. For example, 10 N·m = 88.51 in·lb.
Kilogram-centimetres to Newton-metres:
Multiply the torque value by 0.09807. For instance, 10 kgf·cm = 0.9807 N·m.
The importance of calibration and accuracy in torque measurement
Even with the right tools, accuracy doesn’t stay fixed forever. Over time, a torque wrench will start to drift. That’s just part of regular use. Wear and tear is the most common cause, but it’s not the only one. Environmental conditions can also have an impact.
Extreme temperatures, humidity or poor storage can all affect how reliable your readings are. That’s where calibration comes in. Regular checks make sure your tools are still operating within the correct tolerances and that your torque measurement remains consistent.
If calibration is ignored, the risk isn’t just inaccurate readings. It’s the knock-on effect, components that are too loose, overtightened fasteners and ultimately reduced product quality or failure in use.
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How to prevent errors in torque measurement
There are many factors that can affect the accuracy of torque measurements, such as incorrect settings, humidity, temperature and miscalibration. But these can be prevented from occurring by following these best practice guidelines:
- Only use high-quality torque wrenches and other torque measurement solutions that are designed for precision.
- Ensure you regularly calibrate your torque measurement tools and follow the manufacturer’s guidelines.
- Always store your torque measurement tools correctly and in the right conditions.
- Remember to avoid storing them in places of extreme heat or humidity, as this can cause their accuracy to drift.
- Make sure any operative is fully-trained to use your chosen torque measurement tools to avoid human error.
Why choose Crane for torque measurement?
With over 50 years of experience, Crane Electronics has built a strong reputation as a global leader in torque management. Our deep understanding of torque measurement, coupled with our expertise in providing reliable solutions, makes us a trusted partner for industries looking to enhance precision and quality.
We specialise in improving accuracy, safety and efficiency in manufacturing environments worldwide. By offering bespoke torque management solutions, we help businesses maintain precise control over torque levels to prevent issues such as torque relaxation.
For more information on our torque measurement products, or if you need assistance with our services, contact Crane Electronics, call us on 01455 25 14 88 or email sales@crane-electronics.com.