The impact wrench may not be the most common tool, but that doesn’t mean it’s not useful – quite the opposite. This tool is now a very important help for those who carry out DIY activities, but above all for professional mechanics who have to work all the time with bolts.
An impact wrench will allow you to tighten or loosen a bolt in the most comfortable way and without having to make any effort: in this article we will explain everything you need to know about these powerful devices so you can choose the one that best suits your needs .
- In impact wrenches the power is given by the torque, measured in Newton-meter (Nm): it is important that this data is correct in order to loosen each fastening element we work with.
- Unlike other devices, impact wrenches being very powerful tools are generally only present in workshops, however the new models are quite versatile and suitable for all budgets.
- As important as the shape and power supply is also the size of the mouth (or nozzle), an essential factor for an impulse adapter that will determine the type of screws with which it will be possible to work: our advice is to choose an interchangeable one.
The best impact wrenches on the market: our selection
We generally find impact wrenches in mechanical workshops, although they are multipurpose tools that day after day are increasingly used in the field of home DIY, mechanics and construction. To help you in your choice, we have studied the market for this product and selected the five best models:
- Ryobi R18IW3-0 ONE +
- TECCPO TDHD02P
- TECCPO TDIW01P
- DeWalt FCF880N
- Makita DTD152
Ryobi R18IW3-0 ONE +
The Ryobi ONE + is a three-speed screwdriver capable of reaching 2900 rpm and 3200 percussions per minute, and generating a maximum moment of 400 N · m. It has a ½ ”chuck and a ¼” adapter is included. It also has 3 LEDs to illuminate the work area. Together with the battery it weighs about 2 kg, remaining light and easy to handle.
It is often used to unscrew car bolts, by enthusiasts but also by professional mechanics, and it seems to satisfy anyone with its power and reliability. We are a bit doubtful about the real possibility of it reaching 400 N · m, but it remains an excellent product. It is sold without battery, or alternatively with 18 V and 4 Ah or 5 Ah batteries.
TECCPO’s TDHD02P variable speed screwdriver reaches 2900 rpm and 4000 percussions per minute, with a moment of 180 N · m. It has a ¼ ”spindle and LED lights. Also included are two 4A batteries, which promise to screw in as many as 300 screws each.
The product amply satisfies users, who consider it robust and powerful. It also includes a large assortment of accessories, and in addition to batteries and chargers you will find a belt clip, a swivel extension, a set of tips and a bag. The included tips don’t seem particularly reliable, but at such a low price point it’s hard to complain.
TECCPO offers a 350 N · m screwdriver, which reaches up to 2000 rpm with 3000 percussions per minute. It has a ½ ”chuck and LED lights under the handle. It is equipped with a pair of 18V and 4A batteries. It is also sold with a hard plastic case, belt hook and 17, 19 and 21mm sockets.
For buyers this is a very good quality, powerful and reliable screwdriver, as well as made of good quality materials despite the low price. Screw in screws and unscrew bolts without difficulty and the batteries last a long time.
The screwdriver proposed by DeWalt mounts a ½ ”chuck, has an entirely rubber handle and an aluminum head. It is designed for tightening with M16 or smaller sockets, reaching a power of 250 W with 2300 rpm, 2700 percussions per minute and a torque of 203 N · m.
The reviews are very positive and it is pointed out that it is a small and light tool, but at the same time powerful and able to generate an excellent boost. It is often used in wheel changing, although the protruding battery can become an impediment. You can buy the screwdriver alone or together with two batteries, charger and carrying case.
The Makita DTD152 has a motor that guarantees 3500 percussions per minute, with a rotation of 2900 rpm and a moment of 180 N · m. A series of LEDs illuminate the work area before, during and after use. It weighs 1.3 kg and has a compact design that makes it measure 137 mm in length. It includes a belt hook.
The product is judged to be light but powerful, and users are very satisfied with it. It is also handy and economical, features that make it perfect for DIY lovers but also professionals looking for a balanced product. It is recommended to equip it with an 18 V battery of at least 4 A.
Shopping Guide: Everything you should know about impact wrenches
Impact wrenches have always been associated with car and tire repair. Even if it is true that we are talking about rather common tools for this type of work, every day we find more and more of them in other contexts such as the steel industry, the mining industry or the aeronautics. Below we offer you our buying guide on impact wrenches.
What is an impact wrench?
Unlike drills, pulse guns therefore do not generate a constant torque: their work could be explained as similar to the action of inserting a manual wrench into a bolt or screw that we want to loosen, at the same time hitting the wrench with a hammer and thus rotating it for short, gradual moments.
How do impact wrenches work?
This hammering action is the main advantage over other similar tools, as it allows to obtain two important benefits that a drill lacks: firstly it exerts much more force and secondly the hammering action tends to dissolve the rust and other deposits that keep the bolt or nut adhering to the surface and prevent its extraction.
What are the advantages of using an impact wrench?
Although the first models were heavy and had only a sense of rotation, today these devices have evolved and are much more compact. Most modern models work with a battery and you can take them in the trunk of your car, which will allow you to perform an emergency change in minutes.
What types of impact wrenches are there on the market?
Below we will analyze these types of impact wrenches in more detail:
|Type of impact wrench||Features|
|Manuals||The original keys.
They work with a hammer.
Although the electric versions are much more comfortable, manual screwdrivers are still a good choice for DIY.
|Tires||They work with compressed air and must be connected to an air compressor.
They consume a lot of air and for this you need large compressors.
They have different sizes and powers.
The most modern versions have an ergonomic shape that reduces operator fatigue.
They do not have an adjustment trigger.
They are difficult to regulate.
Ideal for large screws and bolts.
They work very well with oxidized screws.
Do not use them with small screws because they would break them.
|Electric with cable||Power similar to that of pneumatic screwdrivers, although a little lower.
A little larger than pneumatic screwdrivers due to the motor space.
They don’t need a compressor.
They have an adjustment function in the trigger.
|Electric with batteries||They are the most popular ones nowadays.
They allow you to incorporate accessories for bolts of various sizes.
Ideal for working in confined spaces, such as in the case of car engines.
They are powered by 18 to 28 volt (V) lithium-ion batteries.
Less powerful than cable or pneumatic versions.
Infrequent use of the tool will shorten battery life.
They are the best option for very tight or rusty screws.
What should I consider when using air compressors with my impact wrench?
In the following table we see the flow rate and pressure requirements required according to the size of the anvil:
|Dimensions of the anvil||Scope
Feet per minute (cfm)
Liters per minute (lpm)
Kg / cm2
|1 inch (“)||23||651.7||90||6.3|
How do I choose the best anvil size for my impact wrench?
Commonly used impact wrenches (the lightest) have three size anvils: ¼ ”, ½” and ⅜ inch (“). The most powerful guns, used for heavy professional jobs such as truck repairs, have ½ “, ¾” and 1 ″ anvils: it is essential that you choose the most suitable for your job, but above all, the anvil must not be too short.
In the following indicative table we present the compatibility of the anvils and nozzles:
|Anvil Dimensions (inches)||Bochette in mm||Inches in inches|
|1/4||3 – 3.2 – 3.5 – 4 – 4.5 – 5 – 5.5- 6 – 7 – 8 – 9 – 10 – 11 – 12 – 13 – 14||5/32 – 3/16 – 7/32 – ¼ – 9/32 – 5/16 – 11/32 – ⅜ – 7/16 – 1/2|
|3/8||5,5- 6 – 7 – 8 – 9 – 10 – 11 – 12 – 13 – 14 – 15 -16 – 17 – 18 – 19 – 20 – 21 – 22||¼ – 5/16 – 11/32 – ⅜ – 7/16 – ½ – 9/16 – ⅝ – 11/16 – ¾ – 13/16 – ⅞|
|1/2||8 – 9 – 10 – 11 – 12 – 13 – 14 – 15 -16 – 17 – 18 – 19 – 20 – 21 – 22 – 23 – 24 – 25 – 26 – 27 – 28 – 30 – 32||⅜ – 7/16 – ½ – 9/16 – ⅝ – 11/16 – ¾ – 13/16 – ⅞ – 15/16 – 1 – 1-1 / 16 – 1-⅛ – 1-⅝ – 1-3 / 4|
|3/4||19 – 22- 24 – 26 – 27 – 28 – 30 – 32 – 34 – 36 – 38 – 41 – 42 – 45 – 46 – 48 – 50||5/16 – 1-⅛ – 1-3 / 16 – 1-¼ – 1-5 / 16 – 1-⅜ – 1-7 / 16 – 1-½ – 1-¾|
|1||36 – 38 – 41 – 46 – 50 – 54 – 55 – 58 – 60 – 63 – 65 – 67 – 70 – 71 – 75 – 77 – 80||15/16 – 1 – 1-1 / 16 – 1-⅛ – 1-¼ – 1-5 / 16 – 1-1 / 2|
How many revolutions per minute does an impact wrench need?
Lower speeds can delay the completion of a task, so if speed is an essential requirement for your job it will be convenient to choose an impact wrench whose speed and RPM are high, even if you will have to sacrifice some torque or impact to minute. But in the end it will be worth it.
What are impacts per minute (ipm) and how do they affect impact wrenches?
The number of impacts per minute (ipm) as well as the speed must be high as pulse guns require many contacts to tighten or loosen a fastener. If your budget doesn’t allow you to buy a high ipm screwdriver look for one that has a good balance of torque, speed and ipm.
A higher ipm number indicates that there will be more contact between the tool and the fastener which will therefore remain more stable in place. If you find high values also in terms of torque and speed, you will have an almost perfect impact wrench in your hands.
What should i know about impact wrenches if i do heavy work?
If you are considering using an impact wrench for heavy if not very heavy work there are a few things you should keep in mind. For example, you should know that the best are the pneumatic models as they are capable of using a lot of power. You should also choose straight models and models for fixing with both hands as these will be much more powerful than the others.
Below we offer you an indicative table with the most important parameters of impact wrenches in case of heavy work:
|Parameter||Dimensions of the anvil ¾||1 ″ anvil size|
|Air consumption (L / min)||150-159||150|
|Maximum torque (Nm)||1400-1500||3600-4000|
|Impacts per minute||1000-1050||500|
|Weight kg)||3.5 – 6.0||12-13|
|Vibration (m / s2)||20-25||4.5|
|Sound pressure (dBa)||96-99||ninety two|
In the following table we show you the same parameters but this time in case of very heavy work (professional work for the repair of trucks, in the aeronautics sector or in shipyards):
|Parameter||Dimensions of the anvil ¾||1 ″ anvil size||Size of the anvil ½|
|Air consumption (L / min)||181||190||113|
|Maximum torque (Nm)||1630-1700||2440||1100|
|Impacts per minute||1050||900||1270|
|Weight kg)||3.7 – 4.1||6.8 – 7.3||2.2|
|Vibration (m / s2)||10.4||8.5||6.6|
|Sound pressure (dBa)||99.8||104||99.9|
What are the uses and applications of an impact wrench?
Below you will find a table with some of the most common applications of impact wrenches:
|Automobiles||Impact wrenches have always been used in car repair and assembly.
Battery-powered models are an ideal addition to the car, especially for emergencies such as changing a wheel.
Battery-powered models are better than manual ones as you don’t run the risk of twisting your wrist while taking a long trip.
|Garage or mechanical workshops||Impact wrenches have always been present in mechanical workshops.
Quickly and easily tighten screws and bolts.
Battery-powered models allow mechanics to work in confined spaces such as engines.
|Carpentry and decoration||Many furniture requires the use of screws and bolts for assembly.
Impact wrenches do this job very simply.
For external mounting, electric impact wrenches facilitate the removal of rusted bolts.
|Domestic use||Many furniture and appliances contain screws and bolts.
An impact wrench can be very useful for home repair jobs such as changing a sink.
How do you use an impact wrench?
Below we explain step by step how to use an impact wrench:
- Review the manufacturer’s manual carefully. This first step is very important: never use a tool without first reviewing the manufacturer’s manual. You need to familiarize yourself with the tool and its main features.
- Connect the screwdriver. If it has no wires, connect the battery to the charger and wait for it to be fully charged. In the case of electric models, connect the cable to the mains. Some models turn on automatically while others have a switch.
- Choose the head. Depending on the size of the screw you want to loosen you will need to choose the appropriate wrench. Once you have found the correct head, tighten the square socket of the screwdriver. Never change your head when the instrument is on.
- Loosen the screws. Hold the screwdriver with both hands, place it on the screw and pull the trigger. Do not release the trigger until the screw has loosened. If the object has several screws one by one as we explained to you.
- Tighten the screws. Make sure the screw is not already tightened. Place the screwdriver on the head of the screw, adjust the switch for tightening, hold the fixture firmly and pull the trigger. Continue the action until the screw stops rotating: do not over tighten, as you could damage it.
- Turn off the appliance. When finished, turn off the impact wrench. Unplug the power cord or remove the battery from the base. Store the screwdriver and its accessories inside the case.