What is a Robertson Screwdriver?

Understanding the Unique Design and Functionality of a Robertson Screwdriver

When it comes to the world of screwdrivers, many of us are familiar with the standard flat head and Phillips types. However, there’s another screwdriver that has carved out a significant niche due to its unique design and utility – the Robertson screwdriver.

What is a Robertson Screwdriver?

The Robertson screwdriver, named after its inventor Peter Lymburner Robertson, is a tool that stands out in the crowd of various screwdrivers due to its unique design and functionality. The defining characteristic of a Robertson screwdriver is its square-shaped tip, which corresponds to the square recess in the head of a Robertson screw.

One of the main advantages of this design is the secure fit it offers. When the square-tipped screwdriver is inserted into the square-shaped recess of the screw, it fits snugly and securely, minimizing the risk of the tool slipping or ‘camming out’. This feature makes the Robertson screwdriver particularly effective at delivering high torque, which is crucial when dealing with stubborn screws or when a tight fit is required.

Another benefit of the Robertson screwdriver is the ease of one-handed operation. Because the tool fits so securely into the screw head, it’s less likely to slip out, even when only light pressure is applied. This means you can hold the screwdriver in one hand and the material you’re working with in the other, making tasks quicker and easier to manage.

Moreover, the square shape of the Robertson screwdriver tip also helps to reduce wear on the tool. Unlike other types of screwdrivers that can round off or strip the screw head over time, the robust square shape of the Robertson is more durable and long-lasting.

The Robertson screwdriver is widely used in certain industries and regions. For instance, it’s very popular in Canada (where P.L. Robertson was from) and is commonly used in the manufacturing and construction industries due to its ability to bear high torque and resist cam-out.

The Robertson screwdriver is a uniquely designed and highly effective tool that offers several key benefits over other types of screwdrivers. Its square-shaped tip allows for a secure fit, high torque delivery, one-handed operation, and increased durability, making it a valuable addition to any tool kit.

Applications of the Robertson Screwdriver

The Robertson screwdriver, with its unique square-shaped tip, has found applications across a wide range of industries and tasks due to the advantages it brings.

In woodworking and construction, the Robertson screwdriver is often the go-to tool. The reasons for this are twofold: first, the snug fit between the screwdriver and the screw reduces the possibility of stripping the screw head, a common issue encountered with other types of screws.

This makes it particularly useful when dealing with hard woods or dense materials that require a secure and tight connection. Second, the square shape of the Robertson screw allows for higher torque application, making it easier to drive screws into tough materials without the risk of slippage.

Another key area where the Robertson screwdriver shines is in assembly lines. Here, efficiency and speed are of the essence. The design of the Robertson screwdriver allows workers to quickly and securely insert screws with just one hand, freeing up the other hand for other tasks. This increases the overall speed of the assembly process, contributing to improved productivity.

In addition to these industrial applications, the Robertson screwdriver is also commonly used for general household tasks. Whether it’s assembling furniture, mounting a TV bracket, or performing minor repairs, the Robertson screwdriver can provide a stronger, more secure connection compared to many other types of screws.

Interestingly, despite its numerous advantages, the use of Robertson screwdrivers is not ubiquitous across all fields. For instance, in the automotive industry, most of the screws are either Torx or some other proprietary bit, leaving little room for the use of Robertson screwdrivers. However, even in such scenarios, the Robertson screwdriver finds its utility in creative ways, such as in carpentry tasks related to auto body work.

The Robertson screwdriver’s distinct design and superior functionality make it a preferred choice in multiple applications. It offers an optimal balance of efficiency, speed, and strength, making it a valuable tool in various industries and tasks.

Allen (Hex) vs. Robertson Screws

Both Allen (hex) and Robertson screws offer a more secure grip than traditional flat head or Phillips screws. However, there are some key differences. Allen screws have a hexagonal recess and require a hex screwdriver or Allen wrench, while Robertson screws have a square recess and require a Robertson screwdriver.

While both types resist cam-out (the tendency of a screwdriver to slip out of the screw head), Robertson screws are generally considered to offer a better grip due to their square shape. On the other hand, hex screws are more common in applications such as furniture assembly and bicycle repair due to their compatibility with Allen wrenches, which are easier to turn at an angle.

The Prevalence of Robertson Screws

While Robertson screws are not as globally recognized as Phillips or flathead screws, they are quite common in Canada, where P.L. Robertson was from. They are also gaining popularity in other parts of the world, particularly in industries that value their high torque capacity and resistance to cam-out.

Sizes of Robertson Screws

The Robertson screw system, renowned for its square-shaped recess and corresponding screwdriver tip, offers a range of sizes to accommodate various applications. The screws come in five standard sizes, each represented by a different color on the screwdriver handle. This unique color-coding system not only simplifies tool identification but also enhances the user-friendly nature of these tools.

The smallest size, #00, measures 1.77 mm and is paired with an orange-handled screwdriver. This size is often used for fine work, such as assembling small electronics or intricate woodworking projects. It’s ideal for situations where precision is critical, and larger screws could potentially cause damage.

Next in line is the #0 size, measuring 2.38 mm, and it corresponds to a yellow-handled screwdriver. This size is suitable for light-duty applications, like assembling small furniture or installing lightweight hardware.

The #1 size, with a measurement of 2.82 mm, is associated with a green-handled screwdriver. This size is commonly used in residential construction and carpentry, especially when working with softwoods or thin metals.

The #2 size, measuring 3.58 mm, is linked to a red-handled screwdriver. This size is the most common and versatile, suited to a broad range of applications from home improvement tasks to commercial construction jobs. It’s particularly useful for securing heavy-duty materials or working with hardwoods.

Finally, the largest size, #3, measures 4.85 mm and is matched with a black-handled screwdriver. This size is typically used in industrial settings for high-torque applications, such as machinery assembly or heavy construction tasks.

The variety of sizes offered by the Robertson screw system, combined with the color-coded handles, makes it a versatile and user-friendly tool set. Whether you’re dealing with delicate electronics or robust construction materials, there’s a Robertson screw and screwdriver designed to handle the job.


In the realm of screwdrivers, the Robertson Screwdriver stands out with its distinct square-shaped tip and impressive capabilities. Its ability to deliver high torque, resist cam-out, and facilitate one-handed operation makes it a preferred choice for various applications, from industrial assembly lines to home DIY projects. While its prevalence may be regional, the merits of the Robertson screwdriver are undeniable, making it a worthy addition to any toolbox.

In essence, the Robertson Screwdriver is not just another tool; it’s an essential instrument that enhances efficiency, reduces effort, and ensures a secure, tight fit every time. So, whether you’re a seasoned professional or a hands-on hobbyist, investing in a set of Robertson screwdrivers could be a game-changer for your work.