A torque wrench does one job: it tightens a bolt to a set value and then tells you to stop. That matters more than it sounds. An under tightened flange leaks, a wheel nut works loose, and a structural bolt that never reached its preload carries less than the engineer designed for. An over tightened bolt is just as bad: it stretches past its limit, strips the thread or crushes the gasket. If a drawing, a manual or a method statement gives a torque value, a torque wrench is how you prove you met it.
This guide explains the main types, how to pick the right range and drive size, and how to keep a wrench accurate, with examples from the De Neers torque range we supply across the UAE.
The main types of torque wrench
Click type wrenches are the most common. You set the value on the handle scale, pull, and the head gives a click and a small break you can feel when the torque is reached. They are robust, simple and good value, which makes them the standard choice for workshops and site maintenance. A ratcheting head lets you run a nut down without lifting the wrench off it.
Digital torque wrenches show the torque on a screen as you pull and warn you with a beep, a light or a vibration as you approach and reach the target. Many can switch units and store readings, which helps when a job needs a record. They cost more and need batteries, but they remove the guesswork of reading a scale.
Interchangeable head wrenches use one handle with heads that slot into a standard fitting: open ended, ring, ratchet and even pipe wrench heads. One wrench then covers fasteners a socket cannot reach, such as flare nuts on hydraulic lines. The De Neers interchangeable heads come in 9x12, 14x18 and 24x32 fittings, so check that the head fitting matches the handle.
Torque screwdrivers do the same job at small values, for electrical terminals, instruments and electronics, where a normal screwdriver would strip a fine thread.
Torque multipliers use a gearbox to multiply the force of a standard wrench, for very large bolts on cranes, heavy plant and flanges where a long bar would be unsafe or impossible to swing.
Adapters turn an ordinary ratchet into a measuring tool. The De Neers adapters read from 1.5 to 30 Nm up to 20 to 400 Nm depending on the model, a low cost option when you only check torque now and then.
Pick a range with your torque in the middle
The single most useful rule: choose a wrench whose working range puts your usual torque values in the middle of the scale, not at either end. Accuracy is at its best across the middle of the range, and most users avoid the bottom fifth of the scale altogether. If your jobs span 40 to 300 Nm, two wrenches with overlapping ranges will serve you better than one large wrench used near its lower limit.
Write down the torque values you actually use, from the manuals, drawings and method statements, before you buy. It is the fastest way to see whether you need one wrench or two.
Choose the drive size
The drive size follows the size of the fasteners and the torque:
- 1/4 inch drive: small fasteners and low values, such as instruments and light assemblies.
- 3/8 inch drive: light mechanical and automotive work.
- 1/2 inch drive: the general purpose workshop size for most mechanical maintenance.
- 3/4 inch drive: heavy plant, trucks and large flange bolts.
- 1 inch drive: very high values on heavy equipment and structural work.
The De Neers range covers click wrenches in 3/8, 1/2, 3/4 and 1 inch drive, ratcheting click wrenches across the same sizes, and digital wrenches from 1/4 to 3/4 inch drive.
Accuracy and calibration
A torque wrench is a measuring instrument, so treat it like one. ISO 6789 is the international standard for hand torque tools. It sets how a wrench is tested and how far its reading may stray from the true value; for most click wrenches above 10 Nm, that is within plus or minus 4 percent.
Every wrench drifts with use. The usual practice, and the recommendation in ISO 6789, is to recalibrate every 12 months or every 5,000 cycles, whichever comes first, and immediately after the wrench is dropped or overloaded. Most quality systems and client audits in the UAE expect to see a current calibration certificate for any torque tool used on their job.
Each De Neers click torque wrench is supplied in a plastic case with a calibration certificate, and the range is made generally conforming to IS 6789-2008, as stated in the De Neers catalogue.
How to use and look after a click wrench
- Set the value, then lock the handle if the wrench has a lock, so it cannot drift while you work.
- Pull smoothly, at the centre of the handle grip. Jerking the wrench overshoots the value, and pulling near the head changes the reading.
- Stop at the first click. Pulling again after the click adds torque the wrench does not measure.
- Never use it to loosen bolts, and never use it as a breaker bar or a hammer.
- Store it at its lowest setting, in its case. Leaving the spring loaded at a high value weakens it and the wrench reads wrong.
- Keep it out of the sun and the back of the pickup. Heat, sand and knocks on UAE sites are hard on any instrument.
Units
Torque is given in newton metres (Nm) in most UAE drawings and European manuals, and in pound feet (lbf ft) in many American ones. One Nm is about 0.74 lbf ft, and one lbf ft is about 1.36 Nm. Most click wrenches show both scales; digital wrenches switch between them.
Buying a torque wrench in the UAE
Prior Safe is the exclusive Authorized Distributor of De Neers hand tools in the GCC. The full torque range is listed with every size and its MRP in AED on our torque wrenches page, including click torque wrenches, digital torque wrenches, interchangeable head wrenches and torque multipliers. Pair them with the right sockets for the fasteners you work on.
We deliver from Ajman to every emirate within 1 to 2 working days, with dealer pricing for contractors, workshops and resellers. Send us the torque values and drive sizes you need on WhatsApp at +971 58 582 3239 and we will recommend a wrench and quote.
Frequently Asked Questions
What size torque wrench do I need?
Choose the range first: your usual torque values should sit in the middle of the wrench's scale. Then match the drive size to the fasteners, with 1/2 inch drive covering most workshop maintenance.
Is a digital torque wrench better than a click wrench?
A digital wrench shows the reading as you pull and can store results, which helps when a job needs a record. A click wrench is simpler, needs no batteries and costs less. Both are accurate when calibrated.
How often should a torque wrench be calibrated?
ISO 6789 recommends every 12 months or 5,000 cycles, whichever comes first, and straight away after a drop or an overload.
Can I use a torque wrench to loosen bolts?
No. Loosening a tight bolt can overload the mechanism and throw the calibration out. Use a breaker bar or a standard wrench to loosen.
Why should I store a click wrench at its lowest setting?
A click wrench measures with a spring. Leaving it compressed at a high setting weakens the spring over time, and the wrench starts to click early.
