Most commonly used to provide mechanical advantage and grip when turning objects or to prevent objects form turning, a wrench (or 'spanner' as it is widely called in some parts of the world) is the single most used tool in any workshop.
But how do you use them correctly?
1. The right size wrench
Use the correct size wrench, the wrong size will damage the fastening making it more difficult to tighten or loosen. It might also damage the wrench.
2. The right type of wrench
Use the wrench type that gives you the best access, the most secure hold on the fastening and best turns the fastening (e.g. ratcheting wrenches are very good for turning quickly but fixed wrenches can give much more torque.
3. Keep it clean and dry
After use always check the tools are clean and dry before putting them away, this will help to avoid problems such as corrosion and moving parts seizing or becoming tight.
4. Do not use scaffolding poles or similar
If the fastening will not turn with the tools you are using you need to use a more powerful tool such as a larger tool or even an impact power tool. Do not use bars to increase the leverage - it is dangerous and can break the tool.
5. Do not use a vehicle to turn the nut
Do not fix a wrench on to a fastening and then drive the vehicle to force it to turn - needless to say it is dangerous and can break the tools.