Issues of product damage are compounded in the case of high-reliability electronics and when completing third-party contract manufacturing. In the case of high-reliability electronics, such as an airliner’s altimeter or pacemakers and other medical electronics intended for transplant, product failure can come with severe real-life consequences. An altimeter failure may cause an airliner to crash; a pacemaker failure may cause a patient’s heart to stop. These sorts of tragic errors can be reduced, if not prevented, by using proper torque control during assembly to maintain the strength and integrity of the device’s plastic substrate.

When lives are on the line, it’s absolutely necessary for a company to do everything in their power to keep people safe. However, even for less critical electronic applications—such as printers, copiers, game systems, and small drones—torque control to prevent product failure is still highly important, especially when fulfilling third-party manufacturing contracts.

During an in-house production run, improperly torqued products can lead to costly rework and downtime. While fulfilling a third-party manufacturing contract, the repercussions are more severe. If those damaged products aren’t discovered, they may fail after having been included in the contracting company’s final product. At this point, not only is your company exposed to rework and downtime, you also might lose your current contract and future contracts, suffer reputational damage, and be exposed to legal action. When you consider that all this trouble can come from a few over-tightened screws, it’s enough to make you start thinking about how to best control the torque you’re using on your products.

Choosing the Correct Torque Screwdriver for Your Application

Of course, finding the right torque screwdrivers for your electronics assembly manufacturing project isn’t necessarily as simple as going to the local hardware store and seeing what’s on the rack. There are multiple types of screwdrivers capable of delivering precise amounts of torque, each in different ways. The trick is finding the type that’s best for your product and your production process. Once you know which type of screwdriver you need, it’s equally important to find a brand you trust to deliver a quality, consistent, product. Using an inconsistent or incorrectly calibrated torque screwdriver is hardly better than not using a torque screwdriver at all.

There are three main types of torque screwdrivers available: dial, adjustable, and preset. Each of these controls torque using a different mechanism and can be influenced by the operator to various degrees. This chart gives a quick side-by-side comparison of the different types:

Dial Adjustable Preset
Torque Control Mechanism Operator watches display for torque value Adjustable cam-over settings Single preset cam-over setting
Operator Influence Moderate Low None
Versatility High High Low
Application Measure torque/torque verification Field service or maintenance Assembly production

As you can tell, each type of torque screwdriver has its own unique strengths and particular applications it is best suited to. In order to help you select the right screwdriver for your electronics work, here’s a look at each of the three types in a little more detail:

Preset Torque Screwdrivers

Compared to dial and adjustable torque screwdrivers, preset torque screwdrivers are the tool of choice for electronic assembly applications. The best preset screwdrivers use a cam-over technology which prevents over-torquing by using a mechanical action which slips when the torque value is reached. Not many screwdrivers on the market utilize this technology, so it’s important to select the right brand if you wish to eliminate over-torque conditions. Unlike adjustable torque screwdrivers, however, preset torque screwdrivers are pre-set to one torque value of the fastening application. This practically eliminates the possibility of operator error, under-torquing, or over-torquing. So long as the operator is using the correct screwdriver, they will reach the correct torque value.

Preset torque screwdrivers are best used in high-reliability applications in the electronics industry due to their near-perfect torque control abilities. They are particularly useful in assemblies which require many of the same screws and have little margin for error. While quality assurance is always a good idea, a company using preset torque screwdrivers in their assembly can rest easy, with a low expectation of failure or rework. In particular, two types of preset torque screwdrivers stand out for electronics applications: clean room torque screwdrivers, which are suitable for work in controlled environments where any contamination must be prevented, and ESD safe screwdrivers, which can be safely used with sensitive electronic products.

Adjustable Torque Screwdrivers

Adjustable torque screwdrivers allow an operator to quickly and accurately adjust the torque setting on a tool as needed for various applications. As with preset torque screwdrivers, you can find some adjustable torque screwdrivers which feature the cam-over technology that prevents over-torquing. This can be a valuable asset for electronics applications, so we recommend selecting a quality screwdriver with this ability.

It’s important to note that although adjustable torque screwdrivers reduce the extent of operator influence with mechanical controls, they do not eliminate it. In order for an adjustable screwdriver to torque a fastener to the correct level, it must be at the right setting. While it can expected that operators will usually select the right setting before fastening a screw, a margin for error does exist. Operators can accidentally select the wrong setting or forget to change the setting between two different fasteners. Depending on the level of risk involved in your application, quality assurance processes may still be required to ensure that operator error does not cause rework or more costly issues.

In the electronics industry, adjustable torque screwdrivers are ideal for field service and maintenance applications which require quick flexibility to adjust torque settings as compared to preset torque screwdrivers. Some examples include fasteners removed and installed during the routine maintenance of high-priced robots or cell towers. These products require specificity and have many different screw sizes. Backed up by sound quality assurance processes, the mechanical torque limits of these tools provide enough control and reliability to be trusted even in high-reliability electronics applications and for fulfilling third-party contracts with strict requirements.

Dial Torque Screwdrivers

Dial screwdrivers control torque by displaying their current torque value via a display mounted on the shaft of the tool. An operator using a dial torque screwdriver will watch the dial display for the torque reading and stop applying torque when it reaches the fastener’s ideal torque value. A dial torque screwdriver is designed for torque evaluation and torque verification. It is a low cost, versatile tool that can be used for torque auditing or R&D torque testing and product evaluation.

While a versatile measuring tool, these types of torque screwdrivers rely on the operator’s eyesight to interpret the torque value on the dial. As it can be difficult to discern small differences between values and because the angle an operator views the dial at changes their impression of the reading, a certain amount of variation will inherently occur in the torque values of their fasteners.

In the electronics industry, dial screwdrivers are useful for measuring different torque values in a small amount of time. The tool can be used for quality control and assurance, as they can quickly test the torque of fasteners tightened. The dial screwdriver is used in two common torque verification tests: the movement test and the loosening test. These qualities make dial screwdrivers ideal for testing the reliability of products such as consumer electronics, toys, and small appliances.

The Value of Proper Torque Control

As always, selecting the right tool for the job is critical when it comes to using torque screwdrivers for electronics work. Dial screwdrivers are effective for measuring and auditing torque. An adjustable screwdriver allows an operator to quickly and accurately set the tool for various service and maintenance torque applications. Present screwdrivers are typically used for production applications where there is one torque setting required for each fastening application. But although these types are best suited to different applications, all three kinds of torque screwdrivers can justify their cost by the significant improvements they make in efficiency and quality.

No matter what type of electronics assembly your company specializes in, torque control is valuable. In high-reliability applications, or to fulfill specific contract requirements, it’s essential. Understanding which torque screwdriver best fits the needs of your manufacturing process is the first step towards improving your company’s reliability and decreasing the revenue lost to rework and failed products.

For more than half a century, Mountz Torque has been making the best torque control products on the market. We’ve worked with some of the largest electronics companies, and we build our products to match your needs. For high-quality screwdrivers you can rely on for even the most particular assemblies, contact us today.