Impact and torque wrenches are both tools designed to tighten and loosen nuts and bolts, but they do this in very different ways.
Keep reading to find out exactly what situation you should be using either tool in.
Torque Wrench vs Impact Wrench: Pros & Cons
Pros – Torque Wrench
- Precision tightening control
- Effectively silent
Cons – Torque Wrench
Pros – Impact Wrench
- Excessive use won’t tire the user
Cons – Impact Wrench
Torque Wrench vs Impact Wrench – What’s the Difference?
Automatic vs Manual
Torque wrenches are manual devices used to precisely tighten or remove fasteners. They’re operated by hand and work in a similar way to most other spanners and wrenches.
Impact wrenches are automatic devices similar in function to a drill. They’re used for rapidly loosening bolts and lug nuts with the push of a button.
Which one you’ll prefer depends on what you’re using it for. Impact wrenches are great for fast, imprecise work. If you need precision (as you will when you tighten the lug nuts on your car), the torque wrench is for you.
Impact wrenches are loud and heavy. If you use it for long periods of time, it’s advisable that you wear noise protective gear.
On the other hand, torque wrenches are manual devices. They make very little noise and are safe to use in most environments. They’ll be kinder on your ears.
Torque wrenches are extremely precise. You manually set the torque limit when you tighten a fastener to obey strict regulations on car wheel lug nuts.
Impact wrenches are fast and imprecise. They’re good for when you need to rapidly loosen or “spin-on” a fastener, but not much else.
In terms of precision control, you’ll need a torque wrench for those jobs.
Loosening and Removing
Torque wrenches should be used to loosen a lug nut or bolt, but not to remove it.
Use the impact wrench to remove the fastener.
If you try to use an impact wrench to loosen a fastener from its secure position, you’ll warp the fastener, reducing its lifespan.
Torque wrenches let the user adjust the torque output using an electrical limiter or circular clutch. Precise torque control is mostly to allow the user to tighten their lug nuts within certain boundaries set by vehicle regulations.
Impact wrenches are the opposite. They’re optimized for speed and power. They come with a specified power output that depends on the type of wrench.
For electrical wrenches, the torque output depends on the power of the battery.
For pneumatic impact wrenches, the torque output depends on the compressor settings.
a) Electrical Impact Wrenches
Electrical impact wrenches are connected via cord to a mains power source. The force output of the wrench depends on its electrical power output.
b) Battery Powered Cordless Impact Wrenches
Battery-powered impact wrenches are cordless and, as the name suggests, powered by a battery in the handle. The force of the wrench is determined by the electrical power of the battery.
c) Pneumatic Impact Wrenches
Pneumatic impact wrenches use pressurized air from an air compressor to drive the impact mechanism. Compared to electrical counterparts, the torque output of pneumatic wrenches is more dynamic. Simply adjust air compression in your compressor.
Featuring a Newton meter, the dial moves as you apply a force to the wrench, indicating to you your torque output.
Similar to the beam torque wrench, the dial-type comes with a dial in the middle that shows you your force output.
Clickers, perhaps the most common, feature a turning clutch that can be used to adjust the torque output. The wrench clicks to signal that you’ve tightened enough.
The most precise but also the most expensive, digital torque wrenches have a display in the body that shows you exactly how much force you’ve applied.
Impact wrenches are generally more expensive. You’ll be hard pressed to find anything under $50.
Torque wrenches tend to be much more affordable. You could find one for around $20 or less.
If you’re on a bit of a tools budget, torque wrenches will be easier on the wallet.
Torque Wrenches – When to Use Them
Torque wrenches are precision tools meant to prevent overtightening. Some fasteners like the lug nuts in your car wheels must be tightened to a specific level as defined by your vehicle manufacturer.
Torque wrenches will give the user some indication that they have reached the set torque level. This is usually via clicking, digital read-out or dial.
Torque Wrenches – When Not to Use Them
Torque wrenches shouldn’t be used either to “spin-on” or remove a fastener. They are a precision device so when you replace or install a fastener, use an impact wrench to get the fastener into place, then adjust accurately with a torque wrench.
Impact Wrenches – When to Use Them
If you’re installing or removing heavy fasteners like large nuts, bolts, and wheel lug nuts; use an impact wrench. These high-speed, high-power devices are built for low precision fastening.
Impact Wrenches – When Not to Use Them
Impact wrenches are rough and imprecise – avoid using them for tightening. Especially when it comes to the lug nuts of your car, use the impact wrench to “spin-on” the nut into place, then switch to a torque wrench for precision tightening to your vehicle’s specifications.
Using an impact wrench for loosening or tightening risks warping the fastener head. This will dull its edges, making it much harder for tools to gain a grip and therefore shortening the fasteners lifetime.
When Should You Use Both?
Torque wrenches and impact wrenches are very good at what they are designed for, but you should avoid trying to use them for the other’s job.
Using an impact wrench for tightening can warp the fastener head while installing a fastener from start to finish with a torque wrench is slow and impractical.
Use an impact wrench to “spin-on” a fastener into a secure place, then switch to your torque wrench to apply precise force and accurately adjust the fastener.
In the reverse, don’t use the impact wrench to loosen a fastener. Use the torque wrench, then once loosened, switch over to the impact wrench and use it to quickly remove the fastener.