Rusty hand tools. Mini vise, hand vise and clamp.

[WmRMeyers]

Probably a mild acid. Vinegar, soda water, things like that. Then neutralize the acid with a mild base, like baking soda in water, or just rinse thoroughly in water, dry the object, and oil it to prevent further rust.

Muriatic acid, a moderatly strong acid, is used to adjust pH in swimming pools, diluted with water it can be used to remove rust. It can also be dangerous to handle. Enough baking soda will also neutralize it. This was the first thing I learned to use, when I started metalworking. It isn't safe to use, but you can take precautions to keep yourself safe.

Phosphoric acid is often used. It is the active ingredient in Naval Jelly. Also a component of Coca-Cola.

Some use Citric Acid. It's a mild organic acid, and works slowly.

Some use Sulfuric Acid, or Nitric Acid, which are strong acids. Combined in the right proportions they will disolve gold. This is the Aqua Regia of the old metalworkers and jewelers. LOTS of baking soda to neutralize! Individually, and diluted, either can be used with jewelry metals, copper, brass, and bronze as a pickling solution to remove fire scale. They can be very dangerous, too.

For rust, specifically, any of these will work. The milder acids are safer and easier to use, but take longer.

There is also electrolytic rust removal. You can use baking soda, washing soda (sodium carbonate), or lye (sodium hydroxide) with a source of DC electricity to remove rust from steel and iron. It will also disolve non-ferrous metals. Baking soda is a mild base, washing soda is stronger, and lye is very strong, enough so to be dangerous. I prefer washing soda. Unless your skin is very sensitive, you can get it on your skin without suffering serious damage, though you'll want to wash it off as soon as you can.

You can also buy solutions made specifically for removing rust. My personal favorite is EvapoRust. It's not cheap, but it is good. It's also safe to handle, and non-toxic. Metal Rescue is another that I've tried. I don't think it works as well, but that may be a problem with the way I used it, or what I was using it on. It was a bit cheaper when I got it. You'll have to figure out which one (or ones) work best for you. For these, you clean the oil, grease and loose rust off the object, then immerse it. Agitate it once in a while, and check it frequently. These do not harm other materials, like wood or non-ferrous metals. I'm in the USA, so what you have available to you may be different.

Bill