As essential automotive repair tools, torque wrenches prevent accidents. By measuring and controlling the amount of force they apply to bolts, torque wrenches can guarantee that wheels stay on their hubs, the crankshaft keeps spinning, and cars don’t veer off the road.
Different torque wrenches are best suited to different needs, based on factors like size, precision, cost, and torque control mechanism. To help you find the ideal torque wrench for your repair job or business, we’ve put together a simple automotive torque wrench buying guide.
What Types of Torque Wrenches are Used in Auto Repair?
Both hand and pneumatic, or air-powered, torque wrenches are used in auto repair. They differ in terms of the amount of torque they can produce and the accuracy of their torque control mechanism. Three types of hand tools are effective: click wrenches, break-over wrenches, and cam-over wrenches. Click wrenches are the least accurate but most powerful; break-over wrenches are the opposite. Cam-over wrenches are ergonomically friendly, stronger and faster than break-over wrenches, and highly accurate.
Pneumatic tools are faster than hand tools but are limited by the need for air hoses and compressors. While some pneumatic tools use continuous air power, these are not typically strong enough for automotive repair. Conversely, impact drivers, which are unable to easily moderate the amount of torque they produce, frequently provide too much power, damaging bolts and assemblies. Pulse tools with torque control have the speed, torque output, and control needed for auto repair.
For a quick reference on the different types of torque tools used for auto work, try this chart:
|Click Wrenches||Break-Over Wrenches||Cam-Over Wrenches||Pulse Tools|
|Torque Control Mechanism||An audible click and a small deflection inform the operator when the correct torque has been applied.||The wrench deflects 20-70° when the operator applies the correct torque.||An internal clutch slips, preventing the operator from applying too much torque.||Torque is delivered in a series of rapid pulses. An internal hydraulic clutch prevents over-torque.|
|Torque Range||2 – 90 lbf.ft||1.8 – 1,770 lbf.in||3.7 – 885.6 lbf.ft||4.4 – 332 lbf.ft|
How Much Torque Do I Need?
The amount of torque you’ll need to apply depends on the type of bolts you’re tightening, whether you’re making one repair or thousands. Your quality control needs will vary based on how many repairs you intend to make and the criticality of the work.
Bolts used in most automotive repair fall on a spectrum that can be separated into five categories. The work on the lighter end of the spectrum can be done more easily by less experienced workers. The repairs on the heavy side should only be attempted by serious professionals or those with extensive experience or training.
Using this chart to place the type of work you’re looking to do will help you decide between the types of torque wrenches in the previous section:
|Very Light-Duty||Light-Duty||Moderate-Duty||Heavy-Duty||Very Heavy-Duty|
|15-75 ft.lbs||30-150 ft.lbs||50-250 ft.lbs||120-600 ft.lbs||400-1,000+ ft.lbs|
|Cosmetic repairs, mirrors, valve covers, oil plugs, spark plugs.||Lug nuts, head bolts, caliper bolts, most common automotive bolts.||Trailer hitch bolts, axle bolts, hub bolts. Bolts in this range are often safety-critical.||Differentials, transfer cases, driveline components and bearings.||Bolts on performance racing and off-road vehicles. Camshaft sprockets, harmonic resonators.|
Lighter repairs can be accomplished with lighter tools, as they require less torque and are less safety dependent. The accuracy of a click wrench is more than enough for non-sensitive repairs. As repairs increase in seriousness, more accurate torque wrenches provide greater proof of quality and peace of mind.
Professional repair shops, especially those working on high-end, performance tuned or off-road vehicles, will need the fine control and reliability of professional torque tools. In these settings, cam-over wrenches, click wrenches, and pulse wrenches each find a home thanks to their mix of accuracy, power, and speed.
Finding the right torque tools is an important step for professional auto mechanics. While simpler torque wrenches suffice for simpler repairs, higher-level work requires higher-level tools. Using quality torque wrenches makes sure that critical assemblies hold together on the road, preventing break-downs and dangerous accidents. As a result, they provide repair shops with a good track record, which leads to a good reputation and better business.
At Mountz, Inc., we’ve been providing automotive workers with top quality torque tools for half a century. To see our full range of products, shop our store. Contact us anytime to ask a question. To inquire about price, request a quote. If you’d like to see our equipment in person, schedule an appointment.