How to Use a Torque Wrench

A torque wrench prevents the common over-tightening problem

Buy and use a torque wrench to prevent common over-tightening problems and avoid expensive fixes later.

By the DIY experts of The Family Handyman Magazine

Step 1: Learn the advantages of using a torque wrench

You may think you don’t need a torque wrench to install spark plugs or work on your lawn and garden equipment. But studies show that most DIYers overtighten just about everything. And overtightening leads to broken bolts, stripped threads and damaged equipment.

With a torque wrench and the manufacturer’s torque value in hand, the problem is solved: A “clicker” torque wrench makes an audible click when you’ve reached the set torque, and with a “beam”-style wrench, you just watch the scale and stop at the right number.

Torque Wrench Use and Care Tips

Tighten fasteners in two steps—first to half torque and then to final torque.

Clean dirty or rusted threads before tightening, but don’t lubricate them unless instructed to by the equipment manufacturer.

Always dial the wrench back to zero (never below zero) when you’re done with it.

Never use your torque wrench as a breaker bar—that’ll damage the torque mechanism.

Carry it with kid gloves—a single fall can knock the accuracy off by as much as 30 percent. If you do drop it, get it recalibrated (calibration firms listed below) before using it again.

Torque wrench calibration services (304) 253-5729 (800) 328-2897 (530) 268-1860 (888) 682-8675

Step 2: What to look for in a torque wrench

Torque wrenches come in four styles: clicker style, bending beam, dual beam and digital. Dual beam and digital wrenches are the most expensive ($200 to $400), and they're overkill for most of us. You simply don't need to spend that kind of money to get accurate results. As long as you follow our usage tips, you can torque nuts and bolts with any of these wrenches.

Step 3: Set the torque

Did you know there’s a right and a wrong way to tighten lug nuts? Most people think “tighter is better.” Not true. Overtightening lug nuts is the No. 1 cause of brake rotor lateral runout (warp). Warped rotors cause pedal pulsation and can increase your stopping distance. Overtightening is also a great way to break wheel studs. The stud itself doesn’t cost much, but the labor to press out the old stud and insert the new one can be significant.

Spin the lug nuts on by hand. Never coat the stud with grease, oil or antiseize. Lower the jack only enough to bring the tire into contact with the road. Tighten each nut to one-half of the specified torque. Then lower the vehicle completely and tighten each nut to full torque.

Step 4: Lock in the proper torque

Step 5: Tighten in sequence

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