For those who want to clean rust from a particular object, vinegar is the best solution.
Vinegar (acetic acid) removes rust magically, like you see in the pictures. You can also remove rust from bronze objects, jewels, etc.
The method is simple: take a bowl, put the rusty tools inside and pour vinegar until you cover them. For objects with thick rust layer you must let the vinegar act up to 2 days.
After removing the objects from the vinegar, rust will turn into a viscous film that can be easily cleaned with a strong water jet.
If there is any rust left, remove it with a wire brush. Wash the tools with soap and water to remove any remaining vinegar trace.
This is the method we used to remove rust from the tools in the pictures above.