This can work, or not. I posted an experience with my neighbors new HF torque wrench that was so obviously way off. Took it back with him and Manager said to come back after the parking lot sale as all the ones he had on the shelf were way off and the current lot would be sold and a fresh batch in the store. It worked, that was over a year ago and we have checked the replacement (post parking lot) and it is spot on. Lots of DIY calibration videos on you tube.