First patented by Solymon Merrick in 1835, the wrench is also commonly called spanner in British English. Since 1835, it has had an almost universal presence across the world, due to its simple yet effective design.
In the following article, I’ll run through the factors that have lead up to the wrench’s (or spanner; depending on which side of the pond you’re from!) ubiquity. Alongside this, I’ll also talk about other major varieties of wrenches out there and what they have.
The wrench’s simplicity of design is one of the main factors why it has been so widely adapted since it’s inception. The simple design guarantees it is easy-as-pie to duplicate and consequently is able to be mass produced efficiently, yet its extreme effectiveness in the design and employment of torque ensures loosening or tightening bolts is an easy process.
The workings of the wrench are wonderfully simple in fact; it acts as a lever, and because of the length of the tool, it reduces the amount of force you need to apply to fasten or loosen the nut. With adjustable wrenches, one of the most commonly found variations of the wrench, the head of the wrench is adjustable within a given toleration so it is able to accommodate a range of nut sizes. Hence, its effective at adapting to a range of situations.
Conventionally, the wrench head is at a 15 degree angle towards the shaft. This facilitates the use of the tool in close quarters.
Another commercially widespread sort is the socket wrench, the ratchet wrench being the clear winner here. These are normally used by mechanics, as they allow for one way ratcheting – a quick process that decreases the time it takes trade people to do certain tasks like unfastening car wheels.
Finally, you might also be familiar with the Allen wrench (commonly called the Allen key), which are cheap and easily reproduced pre-fabricated wrenches of a individual measurement. Their hexagonally shaped head is not changeable, and they usually accompany specific products that require them for maintenance.