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In the garage power tools are convenient and helpful for maintaining and repairing your vehicle, but hand tools are the crucial instruments every do-it-yourselfer relies on in the shop or garage. A complete assortment of sockets, ratchets and accessories is a necessity for a variety of jobs, from light maintenance to heavier, more complex work. This socket set buyer’s guide will help you find the best one for your needs, or choose an ideal gift for a friend or family member.

Socket Set Basics

Metric, SAE and Whitworth: While SAE, or standard-sized sockets with measurements in inches are widely used for older domestic vehicles, most modern vehicles – both import and domestic – largely use metric hardware, measured in millimeters. Choose a metric or SAE set depending on your needs, or stock your garage with both to ensure you always have the right tool for the job.

Whitworth sockets are a third type, used almost exclusively on British vehicles. Whitworth nominal sizes are in inches like SAE, but reflect the size of a bolt’s shaft, or the inner diameter of a nut. So, a 5/8″ Whitworth socket is larger than a 5/8″ SAE socket. If you work on a classic British vehicle like an MG, Rover, or Jaguar, you may need Whitworth hand tools. If not, stick to SAE and/or metric sizes.

Drive size: Both metric and SAE sockets are available in three drive sizes: ¼-inch, 3/8-inch and ½-inch. Each requires a different ratchet and other accessories like extensions. Smaller sockets typically use smaller drive sizes, while larger sockets use the larger drive sizes. If your socket set is limited to one drive size, choose 3/8-inch drive to cover the majority of sockets you will use. The smallest and largest drive sizes are very useful too, though. Small, ¼-inch drive sockets can sometimes reach small nuts or bolts in tight spots more easily. Large, ½-inch drive sockets can handle more torque and are ideal for larger fasteners that require a longer ratchet or breaker bar to loosen or fully tighten.

Points: Look down the business end of a socket, the part that slides onto a nut or bolt head. What shape do you see? Is it a six-pointed hexagon or a 12-pointed “star”? A six-point socket is stronger than a 12-point socket because its inner walls sit flush against all six sides of the hardware. The advantage of a 12-point socket is convenience; it can slide onto the hardware in any one of 12 positions, so it’s easier to line up. While 12-point sockets are fine for most light work, choose six-point sockets for larger hardware or applications that demand serious torque. Six-point sockets are less likely to slip in this situation.

Shallow vs. deep sockets: Imagine a nut that, when fully tightened, sits an inch below the top of the bolt or stud it attaches to. A normal, shallow socket may not even touch the nut before the top of the stud or bolt hits the end of the socket. In this case, a deep socket is necessary to accommodate the long end of the bolt and fit snugly around the nut. Having some deep sockets on hand can be helpful for situations like this. Without them, you may need a wrench instead of a socket to loosen that nut.

Spark plug sockets are a type of specialty deep socket that every DIYer should have on hand. These are deep enough to reach the bottom of a seated spark plug, and spark plug sockets include a small rubber piece inside to protect the top of the spark plug from damage.

Impact sockets: Not all sockets are designed for use with power tools. If you use a pneumatic or electric impact wrench, you need a set of impact sockets designed for use with these high-torque tools. Tougher construction allows impact sockets to withstand the forces of use with power tools.

Some socket sets include ratchets and accessories like extensions or break bars. If your toolbox is not already equipped with ratchets and extensions, it may be more economical to buy a socket set that includes these crucial pieces. I use extensions so often with my sockets that I typically leave a medium-sized extension on each ratchet at all times. If I can easily reach a piece of hardware without it – and I need plenty of force – I will remove the extension and attach the socket directly to the ratchet.

Check out all the tools & equipment available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on our socket set buyer’s guide, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

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