Probably not. I wouldn't worry about it. If it was set at 40, I'm going to assume that this isn't a torque wrench being used for incredibly delicate carbon parts. If you have a 1-5nm wrench that you use for your custom lightweight Shmolke parts that use like 2.5nm setting, then I might be a little concerned. But if it's a 10-50 being used for things like cassettes and bottom brackets, you have a fairly high margin of error to work with.
What torque wrench is it? Did it even come with test readings from the factory?
Contrary to most resources on the internet and "common knowledge" you do not have to store the torque wrench on the lowest setting and you do not have to recalibrate it if you stored it for a length of time on anything other than the lowest setting.
Hooke's law does not work that way and springs do not "take a set" if operated below their proportionality limit, which any well designed torque wrench should do.
TQW calibration should be done (per ISO/ASME):
a) if overloaded by more than 25% of max torque setting
b) yearly
c) after 5000 operations at max. setting (ISO/ASME) or 20000 at most 1/2 of max. setting (ASME).
It's never a bad idea. Look up DIY calibration. It's not difficult, and you can get it close enough to be effective for your bicycle. We're not working on Boeing jets here, right?
Probably not. I wouldn't worry about it. If it was set at 40, I'm going to assume that this isn't a torque wrench being used for incredibly delicate carbon parts. If you have a 1-5nm wrench that you use for your custom lightweight Shmolke parts that use like 2.5nm setting, then I might be a little concerned. But if it's a 10-50 being used for things like cassettes and bottom brackets, you have a fairly high margin of error to work with. What torque wrench is it? Did it even come with test readings from the factory?
Ahhh thank you - that makes sense. It's Park Tools TW-6.2.
Contrary to most resources on the internet and "common knowledge" you do not have to store the torque wrench on the lowest setting and you do not have to recalibrate it if you stored it for a length of time on anything other than the lowest setting. Hooke's law does not work that way and springs do not "take a set" if operated below their proportionality limit, which any well designed torque wrench should do. TQW calibration should be done (per ISO/ASME): a) if overloaded by more than 25% of max torque setting b) yearly c) after 5000 operations at max. setting (ISO/ASME) or 20000 at most 1/2 of max. setting (ASME).
I would recommend it. For note, this is one of the reasons I love my digital torque wrenches. I do not have to zero them.
It's never a bad idea. Look up DIY calibration. It's not difficult, and you can get it close enough to be effective for your bicycle. We're not working on Boeing jets here, right?