Socket Sets Explained: What Size Do You Need?

Socket sets are one of those tools everyone needs but few people understand properly. Walk into any tool shop and you'll see sets ranging from 20 pieces to 200 pieces, with prices to match. How do you know what you actually need?

Here's our straightforward guide to choosing the right socket set.

Understanding Socket Drives

The "drive" refers to the square hole in the socket that connects to your ratchet. Common sizes are:

1/4" Drive

Small and precise. Best for:

• Electronics and small appliances
• Motorcycle work
• Interior trim and dashboards
• Tight spaces where larger tools won't fit

3/8" Drive

The all-rounder. Handles most automotive and general work. Best for:

• General car maintenance
• Engine work (spark plugs, sensors)
• Suspension components
• Most DIY tasks

1/2" Drive

The heavy hitter. For when you need torque. Best for:

• Wheel nuts and large bolts
• Suspension and steering
• Engine mounts and subframes
• Any fastener that's really tight

Browse our sockets and spanners collection to see the range.

Metric vs Imperial

Modern cars are almost exclusively metric. British, European, Japanese, Korean - all metric. You'll need imperial (SAE) sizes mainly for:

• American vehicles
• Older British cars and bikes
• Some agricultural equipment
• Certain plumbing fittings

For most people, a metric set covers 95% of needs. Add imperial later if you need it.

What Sizes Do You Actually Use?

Most Common Metric Sizes

In order of how often you'll reach for them:

• 10mm - The universal fastener size. You'll use this constantly.
• 13mm - Second most common
• 8mm - Small fasteners, trim, brackets
• 12mm - Common on Japanese cars
• 14mm - Brake components, larger brackets
• 17mm - Wheel nuts on many cars
• 19mm - Wheel nuts, suspension

Less Common But Useful

• 7mm, 9mm, 11mm - Fill gaps in your set
• 15mm, 16mm, 18mm - Various applications
• 21mm, 22mm, 24mm - Large bolts, axle nuts

Deep Sockets vs Standard

Standard sockets work for most bolts where the fastener doesn't have a long threaded section.

Deep sockets are essential for:

• Spark plugs
• Studs with nuts
• Bolts in recessed holes
• Any fastener with a long threaded portion

A good set includes both.

Recommended Set Sizes

Starter Set (40-60 pieces)

Good for occasional DIY. Usually includes 1/4" and 3/8" drive with common metric sizes. Enough for basic maintenance.

Comprehensive Set (100-150 pieces)

The sweet spot for serious DIYers and home mechanics. All three drive sizes, deep and standard sockets, plus accessories like extensions and universal joints.

Professional Set (200+ pieces)

For trade use or if you work on various vehicles. Includes everything plus specialist sockets, Torx, hex bits, and more.

Quality Considerations

Socket quality matters. Cheap sockets:

• Round off bolt heads
• Crack under stress
• Have poor tolerances

Look for chrome vanadium steel construction. Brands like Draper offer good quality at reasonable prices. Check our hand tools selection.

Building Your Collection

You don't have to buy everything at once. Start with a 3/8" drive set covering 8-19mm. Add 1/2" drive for wheel work. Fill gaps as you encounter them.

The 10mm will vanish into another dimension at some point. Buy spares.

Explore our full range of sockets and spanners.