Whether you’re in manufacturing or maintenance, it’s essential to use the right tools in order to get the job done right. After all, the tools you invest in will determine the type of work your business is capable of handling. Understanding the differences between similar tools and choosing correctly between them is, therefore, an important decision which will affect the future of your business.
When it comes to rapidly tightening threaded fasteners, one of the most commonly used tools is the impact driver. Driven by compressed air, an impact driver turns the heads of fasteners with a series of sharp impacts—hence the name. The tool which the impact driver can be most closely compared to is the pulse tool, which also uses compressed air to turn fastener heads with a series of impacts. While they seem similar, significant differences between the two tools can translate to significant differences for your business. To help you pick the right tool, here’s a guide to the capabilities of pulse tools vs. impact drivers.
Comparing Pulse Tools Vs. Impact Drivers
Pulse tools and impact drivers both run on air power. They both deliver torque—the radial force which turns fasteners—in a series of bursts. They’re both fast, and they’re both powerful enough to handle all but the largest bolts. So what’s the difference? In a word: control.
Pulse tools have an internal hydraulic clutch which detects the amount of torque the tool has delivered to each fastener. When the tool reaches a designated amount of torque, which can be adjusted based on the needs of the fastener, the clutch disengages and the tool stops. Impact drivers, which have mechanical instead of hydraulic clutches, do not have this built-in torque control mechanism. So, it’s up to the tool’s operator to stop applying torque at the correct point.
Each fastener has an ideal range of torque. If too little torque is applied, then the fastener won’t hold. Too much and the fastener or the assembly will suffer damage and may fail under stress. So, impact drivers, which lack an automatic torque control mechanism, are more likely to damage fasteners and assemblies due to over-torque conditions compared to pulse tools. A pulse tool will stop before damage is done, even if the operator is unaware of the danger. Impact drivers are more likely to under-torque fasteners as well, as the operator could stop the tool prematurely in an attempt to prevent exactly this type of damage. As such, pulse tools are generally more productive and effective than impact drivers for most fastening applications.
Pulse Tools vs. Impact Drivers: Ergonomics, Price, and Durability
Due to their different clutch styles, pulse tools and impact drivers also vary in terms of their ergonomic effects, their price, and their durability.
Ergonomics considers the effects of job functions on the human body. Impact drivers and pulse tools have different ergonomic effects on their workers. Impact drivers deliver torque in a more violent manner, pushing the head of the fastener into position. This impact affects the operator’s wrists, arms, shoulders, as well as soft tissue and connected body parts. Over time, using an impact driver can harm the tool’s operator. While pulse tools also deliver torque via a series of impacts, their hydraulic clutch acts as a shock absorber, preventing the fastening force from affecting the operator. As such, pulse tool operators are less likely to suffer workplace injuries than users of impact drivers.
One area in which impact drivers are preferable to pulse tools is price. Impact drivers are more cost-effective, making them a popular choice for manufacturers and repair shops. Their mechanical clutch is simpler to produce than the hydraulic mechanism inside pulse tools, which lowers their cost.
However, just as impact drivers can damage fasteners and operators with their motion, they can also damage themselves. Their mechanical clutch relies on metal-on-metal contact to deliver torque. This wears and eventually breaks internal components, which can require frequent maintenance or replacement. The hydraulic clutches in pulse tools mitigate much of this damage. While they still require maintenance, it is not as frequent, onerous, or costly as what impact drivers demand.
So, while the initial sticker price of impact drivers is lower than that of pulse tools, over time, the maintenance costs—not to mention the costs of broken fasteners and workplace injuries—may render impact drivers more expensive than pulse tools.
The lower sticker price of impact drivers may be tempting to companies just getting started or ones which do not have significant financial resources. However, the greater effectiveness and lower total cost of owning pulse tools make them the preferred choice in the long-run for most manufacturing and maintenance companies.