Choosing a wrong wrench can damage the bolt of bike/car which could be dangerous if the bolt is over or under tight.For tightening or loosening a bolt we need a specific wrench, which is a torque wrench. A small torque wrench helps the users to get proper tightening of any fastener.It uses a special mechanism which indicate a click sound or buzz when it reaches to specific torque amount set by user.It is very necessary tool for car tool box because it is used to tight the lug nut of a car. For choosing a appropriate torque wrench for your work, you have to know about the bolt size of your vehicle. Most famous brands of torque wrenches are Tekton, Snap-on, Craftsman and CDI.