You can buy torque rods/extensions, that only allow a pre-engineered amount of torque when used with an impact wrench. That way, with your impact wrench at maximum, it will only torque to what it is designed. They're not too expensive, and most tool companies will sell them, either as a kit, or individually.Thank U, My 1/2" impact is about 30 years old, & I check it against one of my torque wrenches to be pretty accurate..