How to choose a socket set: drive sizes, SAE vs. metric, and 6- vs. 12-point

A socket set turns bolts and nuts faster and more securely than an adjustable wrench, and it's less likely to round off the corners. Choosing one comes down to drive size, measurement system and socket type.

Drive sizes

The drive size is the square opening where the socket connects to the ratchet.

Drive	Typical use
1/4 inch	Small fasteners, electronics, appliances, tight spaces
3/8 inch	The all-rounder: bikes, mowers, most car work
1/2 inch	Large, tight fasteners: lug nuts, suspension parts

If you buy only one, 3/8 inch covers the most home and car jobs. Many sets combine 1/4 and 3/8 inch.

SAE and metric

• SAE (inch) sizes are used on many older American products.
• Metric sizes are used on most cars and many modern products.

A set with both avoids the frustration of finding a socket that's almost right. Using the wrong system can round off a bolt.

6-point vs. 12-point

• 6-point sockets grip the flat sides of a bolt and are less likely to round it off. Better for stuck or high-torque fasteners.
• 12-point sockets fit onto the bolt in more positions, handy in tight spaces where the ratchet can't swing far.

Many people prefer 6-point for general use.

Shallow vs. deep

• Shallow sockets suit most bolts and fit in tight spaces.
• Deep sockets reach nuts on long threaded bolts, like those on some furniture, plumbing and suspension parts.

Ratchets and extras

• Fine-tooth ratchets need less swing to turn, useful in tight spots.
• Extensions and universal joints help reach awkward bolts.
• A breaker bar gives more leverage for stuck fasteners.
• A case with labeled slots makes it easy to see what's missing.

Impact sockets

If you use an impact wrench or impact driver with socket adapters, use impact-rated sockets, usually black. Standard chrome sockets are harder and more brittle and can crack under impact.

Questions people ask

What socket sizes do I need for a car?

Most modern cars mainly use metric sizes, commonly 8 mm to 19 mm, plus larger sizes for lug nuts. Check your vehicle's manual.

Is a bigger socket set better?

Not always. Large sets often include rarely used sizes. Look for good coverage of common sizes in both SAE and metric, plus a solid ratchet.

Can I use a socket set with my drill?

With a hex shank socket adapter, you can drive sockets with a drill or impact driver. Use impact-rated sockets with impact tools.