Most people have different tools in their collection. If you want to add tightening and loosening tools in your box, you may wonder: what is the difference between torque wrench vs impact wrench.
Most tightening and loosening tools have the knack of looking the same, well, to a person who is not experienced.
In this website though, we are trying to demystify different types of tools. For instance, in another post, we looked at torque wrench vs breaker bar. We also concluded that you might need to buy both tools.
You will find that these two tools can perform many of the same duties. However, some outstanding differences make it impossible to use one tool in place of the other.
Torque wrench: what’s it and how does it work?
This tool measures torque on bolts, nuts and other fasteners. You can only use it for tightening but not loosening fasteners.
As we discussed in an earlier article on what is a torque wrench, we saw that this tool comes in many types. Some are manual type torque wrenches while some are electronic.
Some come in electric form and others in pneumatic form. You can use the last two where you need heavy application of torque.
This is easily the most important tool you must have in your collection if you are a car guy. If you own a motorcycle and you want to do your own repair and maintenance, you need a torque wrench.
For sensitive car, motorcycle, oil refineries, drilling rigs and other applications that operate under high pressure, the fasteners are torque-sensitive.
Torque refers to the twisting force applied to tighten a fastener. The physics behind all this is a whole lot. Luckily, you don’t need to go there because the manufacturers of these fasteners give a torque rating for each.
A torque wrench measures the amount of force you want to apply on the fastener. If you’re repairing your car or motorcycle, check the service manual to see the torque you should apply on the fasteners.
Torque wrench benefits
When you use the torque wrench on torque sensitive fasteners, you are going to prevent fastener thread damage as well as damage to the parts the fasteners hold.
A torque wrench is manual
Well, not all the time, but there is also the pneumatic torque wrench that uses air, and it is very good for heavy duty applications.
However, most of the torque wrenches in the market are manual, but that has the benefit of making them affordable, easy to maintain and use.
We have electronic/digital torque wrenches, but they too require you to use your body weight or arm power to tighten fasteners. For these ones, you will need to replace batteries when they go down, or recharge them if they are rechargeable.
Precise torque
This is the main reason for buying a torque wrench, so that you can apply precise torque. If a certain fastener requires precise torque, anything less than that is a big risk.
Likewise, anything higher than the manufacturer-given torque value can damage the threads or bust the fasteners.
You need to torque the wheel lugs to the precise torque level. If you over-tighten them, you can strip them. If you under-tighten them, they can run loose when your car is at speed and cause accidents.
In the engine bay, we have many torque sensitive parts. These include the oil sump, cylinder head and the spark plugs. You must never use a regular wrench on these parts.
To do your motorbike repair, you need the best torque wrench for motorbikes. These two-wheelers have hundreds of fasteners.
Some need precise torque and some don’t. In your collection, get torque as well as regular wrenches.
Good for sensitive jobs
In another post, we looked at the best torque wrenches for gunsmithing. Guns are very sensitive and precise, so it’s vital to use the proper tools, especially when you are mounting the scope base or rings.
In addition, a rifle has many fasteners in the form of screws, bolts and nuts. It is vital that you use a torque driver or wrench to tighten these ones. If you do not, you could strip their threads, mar the tube of your scope or cause other damage to the gun.
Spark plugs are also very torque-sensitive. If you do not tighten them just right, they are going to affect the performance of your engine.
Badly installed spark plugs can affect the fuel consumption rate of your engine. They can also cause serious damage to your cylinder head.
Motorbikes, generators and most other engines that use gasoline use spark plugs. When changing them, torque them to the right level so that you do not affect their performance.
Even your bicycle has many sensitive parts. Many bikes have carbon fiber parts. This is light but resilient material. If you over-tighten such fasteners, the carbon fiber part can break easily.
Makes minimal noise
Apart from the pneumatic wrenches, which we said are air-powered, the manual torque wrenches make no noise at all.
Therefore, you can use them at home, without disturbing your neighbors. The only sound you will hear is a click or a buzzer when it is alerting you that you’ve attained the torque you had set.
Safety
Torque wrenches are designed to enhance your safety when you are working with them. They come with a fixed square head/drive that holds the socket.
To keep the socket in place, they come with a spring loaded ball detent system. It ensures that the socket does not slip off and fall to the floor.
These wrenches are also safe for the fasteners since there is no risk of over-tightening and stripping them.
When this tool attains the final torque, it clicks, buzzes, flashes a light, vibrates or fails (breaks over) so it stops tightening.
Impact wrench: What it is and its benefits
One of the most popular questions on the web today is: is torque wrench the same as impact wrench?
Well, the answer is no. An impact wrench uses impact to loosen or tighten bolts and nuts. By design, this is like an extension of the regular wrench (spanner) only that this time, it uses a power source, which can be electricity, batteries or air.
One of the things you will experience when using an impact wrench is a big hammering action. Of course, this wrench is designed to absorb most of the impact, so you never feel it in your hands. Some can pass minimal vibrations to your hands.
Same as the torque wrenches, the impact wrench finds a lot of use in the automotive world, especially in garages that deal with trucks, buses, tractors and other heavier motorized vehicles.
They also find purpose in the construction industry, in the oil industry, metal work and other industries.
Not to be confused with the impact drivers, an impact wrench uses a ½-inch square drive while the impact driver uses a ¼-inch hex drive.
Impact wrench benefits
This tool has certain benefits that you might not find in other related tools. These benefits make it one of the must-have tools in the garage or workshop. Here are some of the benefits:
Versatility in use
This is a very versatile tool because you can use it to loosen or tighten bolts and nuts. Unlike torque wrenches that can only tighten fasteners, this one does both jobs. This is why it finds most use in the construction, metalwork, oil, and automotive industries.
Good for heavy-duty fasteners
In most cases, you can only use pneumatic torque wrenches to tighten heavy-duty fasteners. These types of wrenches are expensive and hard to find.
That is why we have impact wrenches. They can tighten and loosen big bolts and nuts such as you find on eighteen-wheelers. In the construction industry, people use big bolts and nuts. Because the impact type wrenches have hammering action, they can loosen or tighten these heavy fasteners.
Versatile power source
Impact wrenches can be battery powered, in which case you would have to recharge them as required.
Such tools are costly, especially because they are cordless. When the batteries wear out, you can replace them. Using a cordless power tool is good for field work.
You can also buy the corded/electric type that is best for really big lugs and fasteners. You can use it in the workshop, close to a power source.
Lastly, some impact wrenches use air compressors as their source of power. They are powerful and the set up is not too complicated.
Easy to maintain
Impact wrenches are not calibrated, so they require minimal care and maintenance, as compared to torque wrenches, which can lose calibration if mishandled.
Check the user manual that the tool comes with so that you can store it under good condition. Mostly, it is best to store power tools in the plastic cases they come in. This can keep out the moisture so that the metal parts do not rust.
While these tools are easy to maintain, handle them cautiously so that you do not drop them since replacement parts can be costly.
Good for long hours of work
This is one of the best things about using air impact wrenches. You can do a hefty amount of work without feeling fatigued.
These tools are designed to absorb most of the impact and vibration. In fact, some are so smooth such that you never feel the vibrations getting to your muscles.
If you are using a cordless one, you can use it for as long as the battery lasts.
Pneumatic torque wrench vs impact wrench: Differences
A pneumatic torque wrench and a pneumatic impact wrench may use the same source of power – air, but they are completely different.
They may sound, and even look like the same tool, but they do not work in the same way. Here are the main differences between these two tools:
1. The way they work
The torque wrench is going to apply precise torque, so you should use it for precise tightening jobs. You can use it on torque sensitive parts. This means you need to know how to read and set the torque.
Impact wrenches do not work in the same way. They are more like plug-and-play tools, since there is no torque to set. If you have the right socket for the job, plug it in and use it.
Please note, you will feel more tired if you work long hours with a torquing wrench than when you work with a pneumatic wrench. Your strength is the source of power when torquing fasteners.
2. Torque wrenches are safer
This is another huge difference between these two tools. By design, the torque application wrench has a spring loaded ball detent system. It holds the socket securely so it cannot drop and hit your feet.
Impact wrenches are different. They can be heavy and you have minimal control on the torque application.
An impact wrench is also not very safe for small fasteners. Because of its hammering action, it can damage such fasteners easily. It also does not measure torque so it is easy to strip the bolts and nuts.
3. Torque adjustability
Torque wrenches allow you to adjust the torque level that you want to apply on certain fasteners. Both tools work using torque.
With an impact wrench, you get static torque, so even if a small fastener needs a low level of torque, you cannot adjust it.
A torque wrench enables you to adjust the torque to different levels since fasteners in a car may come in different sizes.
4. Power and performance
Apart from the pneumatic and electric torque wrenches that can apply a high torque level, most of the others can only be used on cars, motorcycles, small boats, RVs and bicycles. The reason for this is because your body weight is the source of power.
An impact wrench on the other hand has a power source. It is electric, pneumatic or cordless (battery-powered). It is very powerful, but you have almost no control on the torque level that it applies on fasteners.
Because it uses a power source, you can use impact wrenches for a long time without feeling tired.
5. Noise levels
Torque wrenches are silent and you can use them inside your garage without any noise going out. Impact wrenches on the other hand make quite a lot of noise, during the hammering (impacting) action.
The noise can be too loud such that you have to wear earplugs. In confined spaces, the noise can feel quite loud. Protect your ears from noise pollution.
6. Working speed
If you work in busy garages where vehicles come in all the time, the best tool is the impact torque wrench because you can work on hundreds of fasteners.
You might have to tighten the most torque-sensitive fasteners to about 70 percent and finish the job with a calibrated torque wrench.
Torque wrenches are only good for small jobs. Using the tool to tighten too many bolts and nuts can cause damage. It can also make the tool lose its calibration. Also, since you work manually, you can only do so much.
Can you torque with an impact wrench?
In some cases, you can. However, this will depend on the fastener since impact wrenches have static torque. This means it is not adjustable.
If an impact wrench can apply a torque of 1500 ft-lb and you have a fastener with the same torque rating, you can use it. However, you have to be cautious because this tool does not measure torque, so it is easy to over tighten or leave it a bit loose.
While this tool is mostly useful for loosening big lugs from cars and trucks, you can use it in situations that require high torque applications.
If you have stubborn bolts and nuts, probably rusted over, you need an impact wrench to remove them. Perhaps you can also use a breaker bar, but this type of wrench is better because it is powered.
Can you set the torque on an impact wrench?
A pneumatic torque wrench, like an impact wrench is good for heavy-duty bolts and nuts
You can regulate the torque that you want on an impact wrench. Regulating is different from the precise action that you get from a torque wrench.
If you control the amount of air pressure that gets into the wrench, you can control the torque. High air pressure is going to give you higher torque and vice versa.
There is the tool air regulator and there is the compressor air regulator. The pressure regulator on the compressor is going to control the working pressure getting to the wrench.
The air regulator for the tool will help you get the torque level that you want. However, note that this will not be as accurate as you would get from a torque wrench.
Wrapping Up
Knowing what to choose between torque wrench vs impact wrench is not too hard. If you handle different types of fasteners in your professional or DIY work, you need to buy both tools.
You can use the torque wrench to tighten small to medium fasteners. Mostly, you use it on parts in the engine bay, car lug nuts, spark plugs and different motorcycle parts.
For stubborn, rusty fasteners, you will need a heavier tool such as a breaker bar or impact wrench to loosen them. However, even the breaker bar might not be able to work on some bolts and nuts that need heavy torque application.
Use the impact wrench on such nuts.