The biggest killer of calibration on torque wrenches with an internal spring is operators who do not back the torque wrench setting off after use.
The best practice is to always return the setting to just under the minimum setting. This allows the spring to return to its natural free length and will help to maintain the calibration of the wrench.
Torque wrenches that are left wound up on high torque settings will generally fail calibration tests compared to ones that have been backed off. This is simply because the free length of the spring on torque wrenches that are left wound up become shorter, therefore causing calibration drop.
Want accuracy for longer? Don't be lazy, don't say you don't have enough time, just back it off, it's up to you.
A lot of people who purchase a digital torque wrench believe that they are self-calibrating and that the calibration of the wrench doesn't need to be checked.
Nothing could be further from the truth.
When you turn on your digital torque wrench, it does a "self-check" (much like a late model motor vehicle when you start it up) to make sure the transducer and internal circuitry are ok, but it doesn't calibrate itself.
So digital torque wrenches need to have their calibration checked just like you would do with any other style of torque wrench (i.e. click type torque wrenches). This is the only way to tell if your digital torque wrench is compliant and to ensure that the torque value shown on the LCD display of the torque wrench is what the torque wrench is actually "pulling".
Digital torque wrenches do go out of calibration and are extremely sensitive to knocks and drops.
Don't be fooled by salesperson tech talk mumbo jumbo and remember that it doesn't matter if it is digital, the wrench still needs to be checked.
Some of the most frequently asked questions that I get are:
What is a good Torque wrench?
Is this Torque wrench any good?
What Torque Wrench do you recommend?
How much does a decent Torque Wrench cost?
A torque wrench is no different to any other product. There are always cheap brands available and then there are the ones that cost a lot more. Cheap torque wrenches generally have no spare parts available. If something goes wrong, the wrench becomes a throw away item, whereas manufacturers of more expensive torque wrenches generally have a vast amount of spare parts available to help keep your torque wrench operating like new, without the need for replacement.
I am a firm believer that "you get what you pay for". Expensive torque wrenches have far more superior operating mechanisms, ratchet assemblies and are made from top quality materials. As well as this, extensive research and development and testing will ensure a product that will meet all expectations.
A torque wrench is used for critical torque applications - "rough enough is good enough" just doesn't cut it.
If you are looking for a good quality torque wrench that will give you years of trouble free use, as well as the confidence in knowing that the correct torque of fasteners is being achieved time after time, look no further than the Norbar product range. Norbar have torque wrenches that will cover every application you require.
My advice simply is to take the guess work out of it and invest in confidence. Upgrade before it is too late.
Torque to Tom for a great price on all Norbar products.
TWCS recommends that this critical application is best performed with a digital, dial or beam style wrench that is within calibration standards. Out of calibration torque wrenches can cause numerous problems, including premature bearing failure. Although these wrenches are generally more expensive, they provide a definitive reading, taking the guess work out of the job and ensuring a high level of repair.
In today's society, Occupational Health and Safety is paramount with businesses constantly looking for safer work practices. If your business deals with voltage, TWCS recommends the use of an insulated torque wrench. Don't put yourself at risk in any voltage applications, whether it be a 12v battery, the ever-expanding high voltage hybrid vehicle market, electrical switchboard or power generation applications, using a non-insulated wrench can lead to a short circuit resulting in serious injury or even death. Insulated torque wrenches provide protection and peace of mind when working with up to 1000 Volts.
The photo shows an example of a "near miss". This wrench was shorted on a battery pack. It has since been replaced with an insulated type torque wrench, providing staff with a safer work practice.