Defining a wrench
In English, a wrench generally refers to adjustable wrenches, which have a moveable lower jaw to adjust to different size nuts and bolts. They’re great because one tool will cover a wide variety of different size fastenings in both metric and imperial – although there is still a minimum and maximum size to watch out for.
The downside, however, is that wrenches are typically quite bulky tools – especially around the jaws – which makes it difficult to use them in narrow spaces or for precision work, which is especially relevant when thinking about automotive jobs. Because they aren’t size-specific, there’s also arguably more risk of rounding the fastening, which can lead to frustration and cost of replacement.
Defining a spanner
Spanners are size-specific. The most common is the combination spanner, which has a closed – ‘box’ – end and an open end to help with different access points, although there are a wide variety of different types such as double box or offset spanners.
The head is slimmer, meaning that it’s easier to fit into narrower spaces and the size-specific nature lessens the risk of rounding. If you know which size you require, then you’ll get the job done quicker as you don’t have to adjust the tool each time, and there is a certain satisfaction from using the ‘right tool for the job’.
