There’s perhaps no tool more ubiquitous, more essential to a workshop than the screwdriver. This handy tool has been a toolbox and workbench mainstay since the flat head screwdriver was invented back in the 1500s.
And though the flat head screwdriver hasn’t changed much over the centuries, there have been plenty of challengers that have improved upon basic screwdriver technology beginning with the Phillips head screwdriver, and more recently with Torx screwdrivers.
This in-depth guide will take a deep dive into the world of screwdrivers so you can decide between the different types of screwdrivers you need for your workbench.
The tried and true manual screwdriver consists of a handle attached to a metal rod that extends to the tip. Manual screwdrivers work on the left loosey righty tighty principle – twisting the screwdriver clockwise tightens while turning it counterclockwise loosens. Manual screwdrivers vary in tip size and length to suit different size fasteners.
A ratcheting screwdriver is a step up in functionality and ease-of-use over the manual screwdriver. The ratcheting screwdriver is similar in appearance to the traditional one but has an oversized handle that houses a ratcheting mechanism.
When turned in one direction, the bit turns with the handle. When turned in the opposite direction, the handle turns but does not engage the bit.
This design allows the user to reposition their hand for another turn without having to remove the tip of the screwdriver from the screw to do so, hence speeding up the screwing or unscrewing action. A switch near the handle toggles the ratcheting actions between tightening and loosening.
Unlike standard screwdrivers that have a fixed tip, most ratcheting screwdrivers have a socket that holds a screwdriver bit. This makes the screwdriver more versatile, allowing it to work with a variety of bit sizes and types.
Some ratcheting screwdrivers have handles that allow them to hold various bits for convenience.
Types of screwdriver heads
Picking the best screwdriver tip for the job will ensure you don’t strip your fastener when driving or removing them. Here’s more on the different types of screwdriver tips.
Flat head screwdriver
Flat head screwdrivers, also known as slotted or flat blade screwdrivers, have a flat tip that fits into slotted screws. A good flat head screwdriver’s tip will be squared off as opposed to tapered like a knife blade.
Flat head screwdrivers come in a broad range of tip widths and lengths to fit everything from tiny slotted screws found on eyeglasses to large bolts. The two most common sizes are 3/16-inch by 6 inches and 1/4-inch by 4-inches.
When selecting a flathead screwdriver size, the tip should fit snugly into the slot on the screw head with little to no wiggle room thereby providing maximum torque while preventing damage to the screw head.
The once ubiquitous flat head screwdriver isn’t as useful as its successor the Phillips head screwdriver, which is less prone to sliding out of the screw head while under pressure.
While this means flat head screwdrivers aren’t as popular as other different screwdriver heads, they still have their place. Slotted screws are still the preferred fastener in applications in which aesthetics are important and little torque is required.
Brass single-slotted screws can still be found on antique furniture, and their clean look and ability to hold paint make them the fastener of choice for most light switch and outlet covers.
Phillips head screwdriver
The Phillips head screwdriver, which was invented in 1933 by Henry Phillips for the auto industry, has a cross-shaped tip with a pointed end.
The tip fits snugly into the cross-shaped slots in Phillips head screws, allowing it to generate more torque than a flathead screwdriver.
A Phillips head screwdriver’s pointed tip is designed to pull out or “cam out” of the screw head when it faces a certain amount of resistance, letting the operator know that the screw is tight enough.
While that cam-out design was handy for 1930s factory workers that had to manually drive in screws on an automobile assembly line, it’s a feature that frustrates modern-day DIYers. The cam-out design makes it more difficult to manually tighten or loosen stubborn screws. This can lead to stripped screw heads when combined with the torque and speed of a power driver.
Today, Phillips head screws are the most widely used screw fasteners and are common in woodworking. They can be found in a variety of carpentry, automotive, and electronics applications. Given how ubiquitous these fasteners are, no workshop or toolbox is complete without at least #1 and #2 Phillips head screwdrivers.
Square head screwdriver
The Square screwdriver, also known as the Robertson screwdriver, after the Canadian who invented it in the early twentieth century, has a tapered square head. This screwdriver works with screws that have a square-shaped slot.
Unlike Phillips head screwdrivers that are designed to pull out of the screw head when they reach a certain torsional force, the square head screwdriver has no such cam-out feature.
The square head screwdriver can apply much greater torque to its compatible square-headed screws, making it better equipped to drive longer screws through denser materials.
You won’t find square screwdrivers on many workbenches since the torque a Phillips head screwdriver offers is more than enough for most manual applications. However, they are increasingly popular screwdriver bits for power drills and impact drivers.
That’s because square-headed screw bits are less likely to cam out of the screw head under the high speeds and torsional forces a power driver creates. This makes the square-headed screw bit a popular choice for securing decking and other tough jobs that require an impact driver.
Allen head screwdriver
Anyone who ever had to assemble a piece of furniture bought from Ikea is intimately familiar with this type of screwdriver.
Allen wrenches, also called hex wrenches, often come free with prefab furniture that you must assemble yourself. And while this hand tool is technically called a “wrench,” it functions more like a screwdriver.
Unlike a traditional screwdriver with a steel rod with a tip attached to a handle, Allen wrenches have an L-shaped steel road with a hexagonal head.
Allen wrenches are used to drive in screws with hexagon-shaped holes. They come in a broad range of sizes with 1/16 inch, 3/16 inch, and 5/16 inch being the most common.
Allen drive cap screws have thick shanks that make them ideal for holding together prefab assemble-it-yourself furniture. Since Allen wrenches are typically included with this furniture, it’s not as essential in your toolbox as a flat head or Phillips head screwdriver.
Hex screws are also commonly used on bicycles, cars, and electronics, making a good set of Allen wrenches a necessity for anyone who owns or works on these machines.
Torx screwdrivers first appeared in the 60s as an alternative to hex screws and are characterized by the six rounded points that give the tip its characteristic star head screwdriver shape.
This design creates a tight connection with Torx screws that makes the screwdriver tip much less likely to slip under high torsional forces than a Phillips head screwdriver. This makes them ideal for use with power tools that produce a lot of torque and speed.
There are also Torx security screwdrivers that work with Torx security screws. These have the same shape as a Torx screw but have a small pin in the center that prevents a standard Torx screwdriver from engaging with the screw head.
This type of screw will only connect to the less common Torx security screwdriver, which has a hole that accepts that pin.
Like the Robertson screwdriver, this star head screwdriver offers superior torque (hence the name) over conventional Phillips or flat head screwdrivers. Larger Torx bits are often used with power drivers in carpentry projects, such as in a deck construction project.
Smaller Torx screws work on electronics, including smart devices and computers.
With its cross-shaped pointed head, the Pozidrive is commonly mistaken for a Phillips head screwdriver. But looks are deceiving. A closer inspection reveals that the Pozidrive actually has eight points versus the four of a Phillips head screwdriver.
It has a cross design plus a shallower cross that sits at a 45-degree angle from the larger one. This design reduces but doesn’t eliminate the cam-out effect of the pointed cross shape.
As with some of the other screws on this list, Pozidrive screws are used in situations that require more torque and can be used in the same applications as
What are the main types of screwdriver heads?
Phillips head and flat head are the two main screwdriver types. While flat head screws are still used in certain carpentry applications and with antique furniture, Phillips has mainly replaced the flathead screwdriver. Less common but still popular screw heads include square, Torx, and Allen.
Which screwdriver head is best?
That depends on the application. For everyday use, the Phillips head screwdriver is best as the vast majority of screws one will encounter are Phillips head screws. That said, if you’re using a power driver, square or Torx head have less cam-out than a Phillips head screwdriver, allowing for more torque and speed with less cam-out.