Industry News & New Products

Limit your liability: Accurately tighten and document lugnut settings

by Nate Kuennen | Sep 09, 2022


Close enough is not good enough. Don’t rely on your own judgment or the sound of your impact wrench to determine if lugnuts are properly secured to a wheel. Always torque them to exact vehicle and manufacturer specifications.

Professionally-torqued lugnuts prevent dangerous wheel separations on the highway and limit a mechanic’s liability from a loose wheel causing property damage, personal injury or, in the worst case scenario, a fatal accident.

The internet is littered with videos showing close calls with runaway tires on highways and on busy streets, nearly striking emergency personnel, pedestrians and the motoring public. Don’t risk a loose wheel. Invest in a torque wrench and give yourself peace of mind.

Lugnut specifications range by rim size, stud diameter and vehicle ratings. Passenger tires vary from 70 ft./lbs. to more than 100 ft./lbs. Refer to a vehicle’s owner manual or check available resources online for proper specifications. Here is an example of the torque ranges available with the TorcUP torque wrench.

 Square Drive3/4"1"1"1"
 Min. Torque (ft/lbs)120240500750
 Max. Torque (ft/lbs)500100020003000
 Min. Torque (Nm)1653357001025
 Max. Torque (Nm)660135527004025
 HEIGHT A (w/ battery) (in)10.40”10.40”10.40”10.40”
 HEIGHT A (w/ battery) (mm)265265265265
 LENGTH C (in)8.86”10.97”11.45”13.94”
 LENGTH C (mm)225279291355
 DIAMETER D (in)2.56”2.85”3.09”3.75”
 DIAMETER D (mm)6572.478.595.3
 WEIGHT (w/o reaction arm & battery) (lbs)8.311.513.119.6
 WEIGHT (w/o reaction arm & battery) (kg)
 WEIGHT (w/ reaction arm & battery) (lbs)10.414.515.922.5
 WEIGHT (w/ reaction arm & battery) (kg)
 RPM at Min. Torque12220.5
 RPM at Max. Torque20852


Improper implications

Undertightening a lugnut will put additional strain on the remaining lugnuts and will eventually cause them to fatigue, loosen and separate. Relaxed lugnuts will also cause the lug holes to elongate and become oblong, thus ruining the rim.

An overtightened lugnut is just as dangerous. Too much force can strip the threads and cause them to stretch, effectively losing their clamping pressure. Over-exertion on the wheel stud can also force them to crack and break off.

The intent behind properly-torqued lugnuts is to prevent wheel separations. One study found “fastener failure” was to blame in 85 percent of reported wheel separation accidents. Don’t become part of that statistic and always follow manufacturer recommendations.

Each time a wheel is removed–whether for tire rotation, new tires or other routine wheel maintenance–the lugnuts need to be torqued accurately before the vehicle leaves the shop. They should also be rechecked two more times in the first 100 miles.


Invest in a quality torque wrench 


A properly calibrated torque wrench will prevent wheel separation and avoid any unnecessary exposure to risk. Several torque wrenches are available in the automotive market, from manual “click” wrenches to battery-powered models. 

At Zip’s AW Direct, we sell and recommend the TorcUP, a quality, durable cordless unit delivering digital precision and offering reduced user fatigue. Click here for complete details on the six options available.

With the TorcUP, you can accurately tighten a lugnut to exact specifications with less effort and greater convenience. This cordless unit frees yourself from manual lever-type torque wrenches and improves confidence, knowing you’ve accurately tightened a lugnut.

The TorcUP also allows you to reach inside a wheel well without a cumbersome lever getting in the way. For safety, yellow “reaction arms” are available to brace against or lock onto neighboring lugnuts to absorb the force generated by this power-packed wrench.

A digital readout at the base of the TorcUP wrench allows you to input the exact torque setting. To set it, press the up and down arrows. You can switch between standard and metric readings by pressing both arrows simultaneously. 



At a max RPM of 20, the TorcUP wrench spins slowly and deliberately and then stops turning when the torque setting is achieved. To improve your efficiency, you can use a standard impact wrench to tighten the nut and then switch to the TorqUP wrench for the final torque setting.

Please note the TorcUP does not record individual torque settings. We recommend documenting each wheel setting and then listing that information on the customer’s invoice. This will limit your exposure to risk once the vehicle leaves the shop.

Accurate recordkeeping and properly tightening lugnuts are the hallmarks of a professional automotive technician. You don’t cut corners and have the safety and best interest of your customers and the motoring public in mind. Invest in a TorcUP wrench and sleep good at night.