How to choose the best impact wrench for your application


With many different options on the market, it can be challenging to know what features to look out for when selecting an impact wrench. This guide provides a brief overview of the technology and outlines some simple steps to help you get started. 

Get familiar with the mechanics

An impact wrench, also known as an impact driver or an impact gun, is designed to tighten or untighten bolts. It is commonly used in mechanical and industrial applications, for example when changing tires and disassembling car wheels, or performing maintenance on oil platforms. There are electrical, battery-powered, or pneumatic options available, each associated with different benefits and challenges. 

The operating principle is relatively simple. An impact mechanism composed of an anvil, an impactor (hammer) and a spring, enables the wrench to tighten and untighten as required. The tool accumulates energy by the hammer cage over one or more revolutions and once the hammer hits the output shaft (anvil), it creates the tightening or untightening torque. 

Assess your requirements

It is good to bear in mind that there is no one-size-fits-all solution. The desired torque range, power requirements and the impact mechanism’s design may vary depending on the job. As the latter affects the weight, vibration, speed and durability of the tool, it can have a considerable impact on user comfort and suitability for the task. To start the selection process, first consider:

  1. What are you looking for in a tool: is it power, efficiency, ergonomics, freedom of movement, or multi-purpose use?
  2. Your environment: how are you going to power the tool?
  3. The torque: range and precision, what does your application require?
  4. The ergonomics of the product: are the vibration and sound levels, the tool design and the proposed accessories a good fit for the job?
  5. The clutch type: is the mechanism capable of delivering the power you require?
  6. The weight and material of the tool: will it be easy to use over long periods and is the material a good match for your working environment?

Take a closer look at tool design

The design of the tool can play a key role in improving productivity. For example, a well-positioned center of gravity is a great benefit, as it enables better support over extended periods, while different handle shapes and trigger positionings can improve user comfort.

Remember that material matters

The material of the tool is another critical consideration. Metallic tools are usually more robust, but also heavy to use over long periods. Composite tools, on the other hand, are much lighter, enabling better maneuverability, but the material has made them less durable. Fortunately, advancements in material development over the last decade have improved the mechanical resistance of composite, improving its strength and making it a good alternative to metal in many applications. 

It is good to remember that the clutch housing and the body of the tool can be made of different materials. When you compare tools, make sure you check which part is composite and which is metal. As a rule of thumb, impact wrenches larger than ¾” tend to be made of metal.



Get the torque level right

Always choose a tool with a maximum torque that is superior to the torque needed for your application. This will reduce the time you spend using the tool and the vibrations you are subjected to. The graph below illustrates the different torque values commonly found in manufacturers’ catalogs. 

Do you use the right impact wrench?

Legend: 


Beware of overtightening! In some applications, for example when changing tires in small vehicles or trucks, tightening requires precision and torque control. Using tools with torque limited functions, coupled with a torque wrench, will optimize the application without overtightening and damaging the studs.

Review bolt size

You can identify the ideal tool square by looking at the size of the thread. If the square is too small compared to the thread, it will not be suitable and is likely to break. However, if the square is too large, it will be too strong and break the screw when tightening it. 

Do not ignore ergonomics, sound and vibration

It is vital to pay attention to factors that affect user safety and ergonomics, such as the sound level and vibration. The sound level is usually governed by the ISO15744 standard and the lower the value, the safer the user experience. The same goes for vibration levels, usually governed by ISO28927: lower vibration levels equal a safer and more comfortable user experience. Some impact systems are designed to enable low vibration levels and safety and comfort can also be further enhanced with the use of vibration-absorbing gloves.


By considering these seven points you will improve safety associated with using tools in the workplace, therefore protecting operators. An additional benefit to these responsible practices is that you will improve efficiency too!

Noise and vibration levels are factors to consider when choosing the tool to use for your application. Usually, when using keys below ¾”, operators are more sensitive to noise. However, above 3/4”, vibrations are more important to ponder.


Try it out

Knowing what you need to consider when looking for the right impact wrench for your application is a good start, but sometimes reviewing technical values is not enough to enable a well-informed purchase decision. To ensure the tool can meet your needs, it is always a good idea to discuss your requirements with the manufacturer and request a trial. Trying the tool out in your target application will give you confidence that it is a good fit for the task, the environment and ultimately, the way you work.

Browse our Air tools here

CP7769 Heavy Duty 3/4" Impact Wrench, Max Torque 1950 Nm

CP7769 Heavy Duty 3/4" Impact Wrench, Max Torque 1950 Nm

$1,095.00 NZD exc.
$1,259.25 NZD inc.

IN STOCK

Add to Cart Add to Cart
CP7763 3/4" Super Duty Impact Wrench, Max Torque 1,630 Nm

CP7763 3/4" Super Duty Impact Wrench, Max Torque 1,630 Nm

$948.27 NZD exc.
$1,090.51 NZD inc.

IN STOCK

Add to Cart Add to Cart
CP7762 3/4" Stubby Impact Wrench, Max Torque 1420 Nm

CP7762 3/4" Stubby Impact Wrench, Max Torque 1420 Nm

$820.87 NZD exc.
$944.00 NZD inc.

IN STOCK

Add to Cart Add to Cart
CP7737 1/2" Angle Impact Wrench, Max Torque 300 Nm

CP7737 1/2" Angle Impact Wrench, Max Torque 300 Nm

$500.00 NZD exc.
$575.00 NZD inc.

IN STOCK

Add to Cart Add to Cart
CP9120CR 4" Air Angle Grinder

CP9120CR 4" Air Angle Grinder

$481.80 NZD exc.
$554.07 NZD inc.

Ask me when I'm back in stock

Product Enquiry Product Enquiry
CP9780 3/4" Heavy Duty Belt Sander

CP9780 3/4" Heavy Duty Belt Sander

$438.00 NZD exc.
$503.70 NZD inc.

IN STOCK

Add to Cart Add to Cart
PIT TOOLS LU-9040H 90 Series 18 Gauge Narrow Crown Stapler

PIT TOOLS LU-9040H 90 Series 18 Gauge Narrow Crown Stapler

$414.03 NZD exc.
$476.13 NZD inc.

IN STOCK

Add to Cart Add to Cart
CP9789 1/2" Heavy Duty Reversible Drill

CP9789 1/2" Heavy Duty Reversible Drill

$395.30 NZD exc.
$454.59 NZD inc.

IN STOCK

Add to Cart Add to Cart
PIT TOOLS LU-50F Combination Brad Nailer - Narrow Crown Stapler

PIT TOOLS LU-50F Combination Brad Nailer - Narrow Crown Stapler

$390.80 NZD exc.
$449.42 NZD inc.

IN STOCK

Add to Cart Add to Cart
Show More


Do you have an idea for our #expertcorner? Let us know!

Useful links:

Book Your Compressor Service

Who we are and how Ash Air can help your business!

Ash Air has been around in New Zealand since 1979, and we’ve grown into a nationwide company with international support and a reputation for quality and reliability.We look after all things compressed air for your business!

  • Reciprocating, Screw, air compressors
  • Vacuum pumps
  • Nitrogen
  • An extensive line of air treatment components

Ash Air's range of Chicago Pneumatic, Alup, Pneumatech, and Quincy compressors are used extensively around the world in industries ranging from oil and gas to food, automotive and farming, and we bring you these world class compressors here in the land of the long white cloud.Our technicians are compressed air equipment experts and are dedicated to addressing customer needs. Supported by a 13 locations nationwide, Ash Air offers one of the widest selections of compressed air equipment and parts available today in New Zealand.

Reliability and Efficiency

With Ash Air compressors, you can count on reliability and high performance for even the most demanding applications. We focus our efforts on the following:

  • Increasing uptime
  • Reducing unexpected repairs
  • Reducing energy consumption
  • Improving the cleanliness of compressed air


Talk to the team today:  CONTACT US CONTACT US

Read more from our #expertcorner


Just like any other equipment, a compressed air installation also requires the necessary maintenance work during its entire lifespan. Even though maintenance costs are only about 5 to 10% of a machine's annual operating costs, failure to budget for maintenance can have potentially disastrous consequences. …


The air dyer is one of the most ignored cooler in the system. A dirty condenser will cause water in the lines, or worse it will cause complete dryer failure. …


Using nitrogen is not about fully replacing CO2, but it can reduce their consumption of CO2 by close to 70%. Using nitrogen is about sustainability. Creating your own nitrogen is easy and will reduce the use of a greenhouse gas, which is better for the environment. It will also save you money as early as month one adding that savings to your bottom line. …


A question that is occasionally asked by our customers to Ash Air is 'what is the cost of compressed air?'  This article looks at the product costs involved with compressed air, as well as minimising the energy cost of compressors and cost allocation. When looking at these factors, we need to realise what causes dropped efficiency of your compressor, leading to increased costs of compressed air. …


You may have great fall protection measures in place to keep employees safe when working at height, but what about their co-workers below? Dropped tools and other falling objects are a major hazard – and one that isn’t always fully addressed.  …


Providing a safe working environment for operators is essential, especially when using pneumatic tools and compressed air. If there is a failure in the air network and the hose is not adequately clamped, the resulting whiplash could be devastating. Failure to follow best practice can result in injuries, associated production downtime and decreased productivity. …


A common questions asked is why do I need an air dryer for my compressor? Typically, air compressors produce water, and although the water can be drained, there can still be aerosol and vapour droplets that are present. This is because water cannoet be compressed. Water can damage your compressor by corroding the valves, pipes and machinery controls, which will cost you time and money to resolve. In the long run, the cost of a new compressor is a small price to pay compared to the loss of production that could potentially arise due to water damage in your compressor.





…


Air compressors can fail for an assortment of different reasons: Normal wear and tear, lifespan and age of the unit, poor maintenance, power surge, install issues are just a few the come to mind. Check out this blog to find out our top 7 tips to ensure your compressor is looked after!  …


That cold, rainy, and in some places icey New Zealand winter is upon us, and with the following air compressor tips, your air system will be prepared with the preferred temperatures, despite the weather outside. Regardless of whether or not it actually snows or freezes up where you live, most winterisation service recommendations are also basic, solid maintenance procedures that will help extend the life and operational efficiencies of air compressors regardless of whether you live in Queenstown or Northland. …


If you're wondering what an air compressor actually is, you've come to the right place. Simply, air compressors convert power in to air that is pressurised which is then used to power air tools such as spray guns. Air compressors are used in a wide range of applications, so naturally if you want one that will be designed for spray painting your vehicle, you want a compressor specifically made for spray guns! This way your compressor will be able to provide the right amount of power to perform the job. …


Compressed air plays a fundamental role in industrial activities. Depending on the type of application, the energy cost of producing compressed air can be very high. Below are some tips to save on you compressor bill. …


Air Compressors are essential tools in a variety of industrial settings. No matter what industry you are in having a reliable air compressor can be a crucial part of getting the job done efficiently. However, like an investment, air compressors require upkeep and maintenance, and eventually will need to be upgraded. But how do you know when it’s time to upgrade your air compressor? Here are some things you need to consider. …


When it comes to laser cutting and other industrial processes, the choice of assist gas is crucial in achieving optimal results. Nitrogen and oxygen are commonly utilized as assist gases, each with its own unique properties and applications. Understanding the characteristics of both gases, will help you to make an informed decision to ensure precision, efficiency, and cost-effectiveness in your operations. …


Mobile air compressors are portable, towable compressors particularly useful for applications that suit the construction and roading industry! You'll often see a mobile compressor being used for sandblasting, irrigation blow-outs, and for quarrying tools such as pneumatic block cutters and rock drills.   …


Did you know that Chicago Pneumatic helped man land on the moon? Notice in this photo of the Apollo 11 landing what appear to be "soccer balls" on top of the capsule. They were inflated through a compressor specially developed by Chicago Pneumatic for NASA. …


Your company purchased an air dryer for your compressor, now where should you install it? One of the most common things we see in the industry are air dryers being stored on top of the compressors. Seems like a wasted space not being used on top of the compressor, right? Wrong. …


When using air compressors, there are many variables that are integral to the quality and effectiveness of your compressed air. When dryer air is necessary, being able to constantly and accurately monitor dew points can be a critical factor to your operation. …


Compressed air plays an integral role in breweries both large and small around the world. From start to finish, all details in the brewing process are managed in fine detail and having the right air compressor is no exception. …


We Kiwi's love our Coffee! Coffee, like all other food & beverage products, must go through a preservation process to keep the beans fresh during storage and packaging before they reach the consumer. Coffee that is not properly stored after it is roasted will lose a large amount of carbon dioxide, which lessens its' flavor and speeds up the staling process. One of the most common ways to preserve the freshness of coffee is the use of nitrogen gas. Learn more here: …


Air compressors are helpful for an enormous range of applications such as air filling, packaging, tools, HVAC control, and more! One possible drawback is the amount of electricity they use; air compressors can be a huge drain on energy if used ​inefficiency...  …


We get it, buying an air compressor is a big financial decision. And now we are suggesting that you need two air compressors, not just one. Ask yourself one question- Can your business still run if your air compressor goes down? …


It’s no secret – air compressors are excellent sources of energy. Not only do they power essential manufacturing elements and applications, but the heat generated as a result of the compressed air processes can be used as a byproduct that offsets other energy costs. However, there’s another form of energy that is also a consequence of the air compression process – sound. …


The emergency stop, "e-stop", is for true emergency situations only. When hitting the e-stop, all power is halted from the machine and the unload process isn't achieved. The emergency stop button is intended to help with possibly hazardous situations that are developing. Common conditions of having to use the e-stop is the misuse of the equipment in ways that weren’t intended, predictable failures not addressed or failing to consider all the foreseeable uses of the compressor.
…


We've put together a list of tips for working safely with air compressors in your environment! We recommend that you always read owners manual before running your compressor. The number one cause for repairs and personal injury is improper use. You've got to remember to use eye protection and hearing protection when operating your air compressor and try to avoid using air compressors in a wet area.  …


Air Compressor Installation Tips Installing Your Reliable Air Compressor

So, you've just bought an efficient and reliable ALUP air compressor? Welcome to the world of compressed air. As your partners in compressed air, we will continue to assist you along your journey. We have provided air compressor installation tips to ensure you get the most out of your air compressor.  …


Air dryers remove any condensation from the air compressed by your air compressor. Questions about them? Find answers to the most frequently asked questions here. …


Power tools are a key to productivity in the oil & gas or the metal working industry. Maintenance and production tasks must be carried out efficiently, however intensive use of vibrating power tools, such as grinders, can expose operators... …


Selective soldering with nitrogen is an essential process in the production of printed circuit boards (PCBs). It is used for bonding components to PCBs that could otherwise be damaged if exposed to a lot of heat. Another area of application are mixed-technology circuit boards with layout constraints.  …


Hydrogen is becoming increasingly important as a promising clean energy carrier – especially with a view to a more climate-friendly future. But have you ever wondered what hydrogen actually is and how it is produced? In this article, we look at the basics and technologies used to produce hydrogen and what makes hydrogen a special element. …


Your passion is vinification, ours is air compressors. 

Compressed air accounts for a large amount of energy consumption in the wine production process, especially in the production of grapes. A big part of wine-making is a result of the work of equipment and is dependent on its efficiency. An air compressor should be located in well ventilated, shaded areas, out of direct sunlight. This includes the inlet for the compressed air system which should be located away from heat sources such as the compressed air outlet, refrigeration or air conditioning plant and equipment. …


Cutting, shaping, drilling, and finishing, compressed air is critical for any machine shop. Shops rely heavily on the compressed air system to assist in a variety of operation processes. Commonly the parts produced are used in the machine industry, car industry or even the aircraft industry. A traditional workday in a machine shop requires the use of air compressors to generate an intermittent or continuous source of pressurized air. What machines commonly require compressed air in the shop? …


Variable Speed Drive compressors  are a game-changer in the world of compressed air. These compressors automatically adjust their operating speeds to match the real-time demand for compressed air. It's an important feature, especially when it comes to energy savings. Surprisingly, the electricity consumed by a compressor can account for the largest portion of its total cost of ownership, not the initial purchase price. On average, VSD technology can reduce energy costs by 35% to 50%, which translates into significant saving …


When an industrial application calls for a steady supply of quality air, more and more users are turning to rotary screw compressors. Their efficiency, reliability and versatility make them a great choice in these cases. But there are countless applications and many different types of rotary screw air compressors. So which one is the right one for you? …


Your tool is stalling, or is not working to its expected performance, and you find yourself asking ‘why is my angle grinder spinning too slowly?’, or ‘why has my pneumatic grinder stopped working?’, read on. …


Lighting tower reminds night, but also refers to diesel engine. In turn, night reminds us of silence, which is not exactly what we associate with an engine... With urban centers becoming increasingly dense and legislation increasingly strict about noise pollution in construction sites, keeping decibels to acceptable levels has been the great challenge of the main construction equipment manufacturers. …


In today’s world of increasing environmental awareness and the drive for sustainable practices, industries are actively seeking innovative solutions to reduce energy consumption and minimize their carbon footprint. If your business uses air compressors, focusing on energy recovery in air compressors is one area to pay attention too.  …


Did you know that 70% of the total cost of compressor installation consists of energy costs?

There are many reasons why saving energy is important for your business as it helps you in many ways to make your business more efficient as well as providing you with many different forms of value. Ash Air's range of Alup products can help you become more energy efficient to help reduce energy bills, reduce your costs and comply with all environmental legislation. …


Exactly what is compressed air? Where does it come from? What is it for? When we compress—or squeeze—air into a small space, we call it compressed air. When humans discovered the ability to compress air, civilisation made a huge leap forward. The reason? Compressed air opened the door to all kinds of new production methods.  …


Compressed air system leaks are indeed a big source of energy waste. Leakage in piping systems have been shown to exhibit leaks of up to 25 percent of the total energy costs. Addressing leaks is one of the first maintenance steps a facility can take to reduce energy costs. …


Think about efficiency for a minute. Every year with constant innovation, things are becoming even more efficient. Everything from electronics to industrial machinery are being developed to get more done faster while using less power. …


The air surrounding us is a mixture of fry air and water vapor. The amount of water in the air depends on the temperature and volume of the gas. The higher the air temperature, the higher the air's ability to absorb more moisture. Find out about compressed air humidity here. …


Investing in an on-site industrial gas generator is a great way to reduce your environmental footprint and your operating costs. Once you have taken this important step, there are some other things you can do to maximize your gas generation energy savings. Here are seven of them. …


For many businesses, preserving energy and becoming more sustainable have become top priorities. That not only saves them money but also makes them more competitive in the future, when demand for “green” products and services will only increase. Not just because governments mandate greater sustainability but also because customers expect it. …


While you relax and read this, do you see an electronic appliance around you? Wondering how could you relate to the current read? We got you! Compressed air is all around, in the electronic appliances you use right now. …


There are many contaminants that can threaten your compressed air system, but moisture is among the most prevalent. You may be thinking, but it’s just water, but water can have a devastating impact on your compressed air system, your production equipment, and your end product. The best way to prevent moisture from contaminating your compressed air is with a dryer. …


Compressed air can be one of the most expensive forms of energy for manufacturing plants, often using more energy than other equipment. One horsepower of compressed air requires eight horsepower of electricity. With many air compressors running at efficiencies as low as 10%, there’s often plenty of room for improvement. Fortunately, 50% of compressed air systems at small- to medium-sized industrial facilities have opportunities for low-cost energy conservation. …


As easy as it would make all of our lives, vacuum pumps are far from being “one size fits all”. Not only do you have the size to consider when choosing a vacuum pump, but more importantly type. I will briefly touch on some of the advantages and disadvantages associated with each vacuum technology we deal with. This should give you a better understanding of where to begin your search... …


AIRnet offers moisture-eliminating drop fittings called Quick Drops! Quick Drops make “drop-tees” obsolete, removing the need for extra parts and pipe, while saving time and money. …


Proper compressor installation and commissioning helps ensure trouble-free startup and long-term reliability. Thorough inspection and critical review during each phase of the installation process eliminates “built-in” deficiencies or problems which c... …


Price is an important consideration when choosing a tool for metalworking applications, but it alone should not be the deciding factor. Other things also contribute to the total cost of ownership, performance, and, ultimately, the overall productivit... …


Are you faced with the decision of whether to switch from purchasing bottled nitrogen or oxygen to on site gas generation? In that case, the decision is easy. You should! Lower costs, the right purity, less transportation emissions, improved safety, no logistics headaches. In all of these areas, on site gas generation is the superior solution. And making the switch is easy. All you need is a gas generator and a supply of compressed air. …


Did you know that one of the largest costs for industrial manufacturers is compressed air? That’s right – anywhere from 12% to 40% of a facility’s total energy costs come from its compressed air installation. This means that finding innovative ways (no matter how small) to increase compressed air efficiency can amount to big savings over the long run! Items like leak elimination, air audits, reduced pressure bands, and reducing unloaded running hours are some of the most popular ways to decrease energy usage – but there are many other actions that you can take. Read on to discover additional ways to reduce your costs and make sure your compressor system is running as efficiently as possible! …

Show More