Hi Frank, thanks for your review. It is unfortunate that your wrench bent. It is the first time I’ve heard of one bending in more than 4 years of selling these. These wrenches are made according to strict JIS standards and exceed the torque specs of M10 bolts (Japanese 14mm hex) by a good margin. However, if you have a seized nut exceeding the torque specs and put your foot or an extension on the wrench and , it will break, like any tool. But perhaps yours had a manufacturing defect.
An M10 bolt's maximum tightening torque depends on its bolt grade and whether the threads are clean and dry or lubricated. For high-strength Grade 10.9 bolts, the maximum torque can range from around 57 to 82 Nm (42 to 60 ft-lbs), while lower-strength Grade 8.8 bolts are torqued to approximately 37-57 Nm (27-42 ft-lbs).
I am curious to know why you did not contact me first before writing this review.
David