Reading a socket set

Chrome vanadium

Cr-V is a steel alloy, and on hand tools it is shorthand for one that takes torque without deforming. A cheap socket in soft steel rounds off inside, and once it has rounded it will round every bolt it touches afterwards. It also resists rust, which matters in a garage that is cold and damp for half the year.

It is worth checking because the alloy is the thing you cannot see and cannot fix later.

Drive size

The drive is the square hole the ratchet fits into, and it decides what the set is for rather than how much of it there is.

1/4 inch

Small fasteners, electronics, interior trim

3/8 inch

The general-purpose size: most car and household work

1/2 inch

Suspension, wheel nuts, anything seized

A set that covers 1/4 and 3/8 handles almost everything a home workshop meets. If you are regularly on wheel nuts you want 1/2 inch as well, and a breaker bar rather than a ratchet.

Six point or twelve point

A six-point socket grips the flats of a nut. A twelve-point grips the corners, and corners are what round off. Twelve point is easier to get onto a fastener in an awkward space, because it engages every 30 degrees instead of every 60.

The rule: twelve point for access, six point for anything tight or rusted.

So what is the piece count for

Mostly the box. A hundred pieces sounds decisive, but it counts every socket, every bit and every adaptor, and a set of 108 with a good ratchet beats a set of 200 with a poor one. Look at the alloy and the drive first, and treat the number as the last question rather than the first.