Life is full of troubles.

Your new stainless steel designer kitchen is a mess of burnt-on grease and fingerprints.
A construction company spattered paint and mortar on the elegant steel-clad walls of your building.
That cookware that costed you an arm and a leg are stained with coffee and have been ruined by the heat.
Your gardener forgot his plain carbon steel pliers on the garden table at your beach house, and rust left a spot on the stainless steel surface.
You know, some things happen to everybody at least once.

Fear no more!

Luckily, stainless steel surfaces are highly resistant to stains and wear. For this reason, they are frequently used in harsh and extreme environments, both at home and in industry. Sinks, professional kitchen furniture, tanks, street furniture, and work tools are subject to dirt, paint, grease, heat, and weather.
These daily attacks can damage the looks of stainless steel. Don't despair: in most cases a cheap and easy solution exists!
    

Daily cleaning of light dirt
Use soap or detergent, or a 1% ammonia solution in warm water. Apply with a cloth or sponge, rinse with clean water and dry.

Clean fingerprints from stainless steel
Soap and warm water are again your best friends. If that doesn't work, try solvents like rubbing alcohol or acetone. Specific commercially-available products can reduce fingerprint marks.

Oil and grease
In order to remove oily and greasy traces you can use rubbing alcohol, acetone, or isopropyl alcohol. On surfaces not in direct contact with food, you can try alkaline detergents.

Tough stains, discoloration, oxidation, water stains
Use mild, non-abrasive cleansers. Apply with a soft cloth or sponge and rinse with clean water. Avoid scouring pastes and chlorine-based products. You can also use cream detergents containing calcium carbonate or citric acid.

Remove paint and ink from steel
Use a specific thinner or paint stripper, based on the paint. Use a nylon or softer brush on textured surfaces. Follow manufacturer's directions.

Burnt-on food and fat
Let it soak in hot water and diluted ammonia or detergent. Remove the grime with a nylon brush and fine abrasive powder if needed. Repeat in case of stubborn stains, and then clean with soap and water. Be careful: abrasive powder can scratch polished surfaces!

Coffee and tea stains
To remove tea stains from kettles, soak them in hot water and sodium carbonate (aka washing soda). For coffee stains, use hot water and sodium bicarbonate (aka baking soda). These products can also be applied with a sponge or a soft cloth.

Limescale, cement and mortar splashes
Use a 10%/15% phosphoric acid solution in warm water. Neutralize with diluted ammonia and rinse with clean water.
On limescale stains you can also dilute one part of vinegar in three parts of water. Apply with a nylon brush. Specific products are commercially available. Pay the utmost attention  when using hydrocloric acid-based product to remove mortar splashes from stainless steel.
To avoid water stains, don't leave drops, especially if your tap water is especially hard and with a high mineral content. You can use a hair dryer or paper towels.

Heating stains or strong discoloration
You can apply non-abrasive or polishing pastes, like those used on car body. Creams are ok on most finishes, but pay attention on very smooth surfaces because they can leave scratches. Except for polished steel, you can use an abrasive pad. Don't forget to use it along the grain and not across it.

Clean exceptional, atypical dirt on stainless steel
Use fine abrasive paste, like the one used on car body repair, then rinse and dry. Go easy on it because matte surfaces may turn smoother. You may have to treat the entire surface and not just the dirty patch, to avoid differences in finish.

Remove rust stains from stainless steel
When mild steel (common non-stainless carbon steel) rusts, it can leave spots on stainless steel. Iron particles from welding, sawing, or other chips, block natural passivation of stainless steel. Rust is thus developed and, in the worst cases, it can evole in "pitting", i.e. localized corrosion.
There are specific commercial products that can deal with these stains. As an alternative, you can try a 10% phosphoric acid solution, then apply diluted ammonia and rinse thoroughly. Oxalic acid is another option, always followed by a water rinse.
A slightly more drastic way of removing rust stains in small areas is to sand them down with fine sandpaper. We advise you to test the result on a hidden area to check the final result. When working on satin or brushed steel, go with the grain and not across it. Don't use common steel wool unless if it's stainless steel wool. Don't use sandpaper you previously used on mild steel.

 

In order not to advertise, we never named any product, but just their type. Ask your shopkeeper. Cleansers must be used according to the manufacturer's specifications, respecting the environment and safety rules. Do not use solvents and other substances that release gas in enclosed spaces.

Do not use sharp or pointed objects that may scratch surfaces. Do not use abrasives or substances containing chlorine, like bleach. Before using harsh chemicals, test them in a hidden area. If you use steel brushes, make sure it's stainless steel to avoid carbon steel contamination.