Torque Wrenches

Torque wrenches are designed for specialised tasks that require an accurate and measured amount of force to be applied to a fastener, like a nut or a bolt. Calibrated to precise standards for tasks that require accurate fixing, only a torque wrench will do.

Cromwell stocks a wide choice of torque wrenches in different drive sizes and shapes from leading brands like Draper®, Norbar® and our own brand, Kennedy®.

What is a torque wrench?

Designed specifically for accurate tightening of fasteners like nuts and bolts, torque wrenches are a calibrated hand tool, in which a socket is placed to match the size of the fastener. A flip-reverse feature allows the user to switch between clockwise and counter-clockwise turning to loosen or tighten the fixing.

Why a torque wrench?

Over tightening of nuts and bolts can strip the threads and make them useless, while an under tightened bolt will work its way loose, which could have disastrous consequences. It's important that a torque wrench is used for safety-critical tasks, like securing wheels to a vehicle to ensure maximum safety.

When are torque wrenches used?

Used widely in a range of professional trades, car mechanics regularly use torque wrenches when servicing or repairing vehicles. Every fixing in a car has a specified torque value that needs to be met for safe use. And each type of vehicle has unique torque specifications that must be followed to prevent damage.

Torque wrench types

Torque wrenches are available in a variety of types that feature different methods of adjustment and readings. Here are a few of the most commonly used:

• Beam   -  Set using a scale to adjust the torque to allow for easy viewing

• Click   -   A twist setting on the handle adjusts the torque measurement and the tool clicks once it's been reached

• Dial   -   Featuring a memory pointer, the torque is displayed on a mechanical dial

• Digital   -   A sensor monitors the torque applied and communicates it on a digital display

• Hydraulic   -   Used in heavy-duty applications, this type uses hydraulics to reach the torque required

Considerations when choosing a torque wrench

• Material - Torque wrenches require a lot of strength to assert the correct force for each torque specification. If you'll be using your torque wrench regularly, go for one that's made with durable materials for a long-lasting tool.

• Calibration - Reputable suppliers will provide a traceable calibration certificate as standard or upon request. To ensure your torque wrench is high quality, make sure you get the calibration certificate.

• Sockets - When purchasing a torque wrench, often the tool is supplied separately from the sockets. These can be purchased separately as individuals or as part of a socket set.

• Grip - Depending on the type of applications the torque wrench will be used for, ensure the tool has a comfortable grip to prevent hand fatigue and strain.

Torque wrench jargon buster

We want to make it easy for you, so here are some key terms that will help you understand the range and applications a little better

What does ISO 6789-1:2017 mean?

ISO 6789-1:2017 refers to the requirements and methods for testing quality and design conformance for hand torque tools.

Let's break it down...

• ISO - International Organisation for Standardisation define the safety requirements for hand torque tools

• 6789 - This is the assigned legislation number

• 1 - This indicates part 1 of the standard that's applicable to the tool in question

• 2017 - This is the year in which the standard was published

FAQs

Do you really need a torque wrench?

If the tightness of the nut or bolt is critical then it's a job for a torque wrench. A torque wrench allows for measured tightness to be applied and prevents over or under-tightening fixings to ensure safe fitting.

What's the difference between a torque wrench and a ratchet?

A torque wrench provides precision torque settings for specialised applications. Ratchets are a form of spanner designed to quickly loosen or tighten fittings.

What can I use if I don't have a torque wrench?

Where specialised applications are concerned, the tightness of bolt fixing is critical to safety. Cromwell does not recommend you use anything other than the correct tool for the job.

Do torque wrenches need to be calibrated?

Torque wrenches are usually calibrated upon purchase with calibration certificates available as standard or on request from most suppliers. However, to ensure your torque wrench remains accurate, regular calibration is a must, with a recommended annual calibration for regularly used torque wrenches. For more information, please see the requirements for calibration certificates described in ISO 6789-2:2017.