How to Remove Rust From Knives

Stainless steel is one of the most common materials for knife blades. It has a lot of excellent properties and while it doesn't rust easily, just like any other type of metal, corrosion can and does happen.

If you’ve brought a beautiful stainless steel knife, the last thing you want is to have to get rid of it because of a little rust. Fortunately, there are things you can do to remove rust on stainless steel surfaces and bring them back to their former glory. In this article, we'll be looking at some easy tips for cleaning stainless steel and how to fix a rusty knife.

Table of contents

What Is Rust and Why Does It Affect Stainless Steel Knives?

The correct term for rust is iron oxide and this is an orange/red substance that appears flaky and is found forming on different types of metal. This rust is created when oxygen and iron react to the presence of moisture. This doesn’t have to be water as there are a lot of other liquids that can have the same effect. Even just leaving your knives in a moist or humid environment could result in them developing rust spots.

Many knives are made from stainless steel and this contains iron as well as other elements like nickel and chromium. Because the material contains iron, that means you can see stainless steel rust. While a lot of stainless steel knives are marketed as being ‘resistant to rust’. However, this claim largely depends on how they’re cared for. Fortunately, the presence of chromium gives stainless steel a protective layer that helps in the fight against rust.

What’s even more interesting is that this protective layer has the ability to reform when it is damaged. However if the chromium is unable to regenerate, that’s when you’ll get rust. In the kitchen, this is normally the case when the layer of chromium is over-exposed to moisture or becomes damaged. What’s more, you have to keep in mind that using certain products on your stainless steel knives can render that protective layer useless. This includes things like harsh dish soap and bleach.

But that isn’t the only thing that can cause your knives to rust. Things like exposure to acid or salt in certain foods or extreme temperatures can all affect the performance of the chromium layer.

How Can I Remove Rust From Stainless Steel Knives?

If you notice that there is rust on your stainless steel knives, this doesn’t mean that you have to throw them out and buy new ones as there are things that you can try as knife rust removers. Of course, if the rust is very severe then it may not be possible to remove it all, but for mild to moderate rust problems, there are a few things you’ll have lying around the house that might tackle the issue. Read on to find out more about our preferred method on how to get rid of rust on knives.


In white vinegar, there is something known as acetic acid and this will fight rust. It’s important to only use white vinegar as a rust remover, as other types may do more harm than good and could stain your knife.

You will only need to soak the knife in white vinegar for about five minutes. If you do it for any longer then this could cause damage.

However, if you find that five minutes isn’t long enough then you may need to combine this method with the following one; using baking soda.

Baking Soda

You can use baking soda as a backup method to the white vinegar method for removing rust, which we have just discussed. However, it’s also ideal if there is just a small amount of rust on the blade.

You will need to make sure that you clean the blade before you start using the baking soda as any debris or dirt will affect how well this method works. Ensure that you use a suitable cleaning product and try to avoid using water as this might just make things worse.

You’ll then need to make a solution of baking soda and water so that you end up with a paste-like substance. Use this to cover all of the affected parts of the blade and leave this for around 60 minutes.

You can then take an old toothbrush or something similar and use this to scrub at the spots of rust.

If the rust is very stubborn then you might need to use steel wool but whatever you use, make sure to only apply gentle pressure to avoid damaging the blade.

When you’re done, you can wash away the solution using a damp cloth. But be sure to thoroughly dry the knife to avoid any future problems with rust.


It might sound as though we’re pulling your leg but it’s true that potatoes are incredibly good at getting rid of rust. This is because they contain something called oxalic acid and this is something that’s found in a variety of cleaning products. This acid dissolves rust and so is perfect for cleaning your rusted stainless steel knives.

There are two ways you might perform this method. For starters, and for knives that aren’t too rusty, you can place the knife into a potato and leave it for a couple of hours. Once you take it out, you can wipe down the knife and any rust should just come away.

For more severely rusted knives, you can combine the power of potato with dish soap and elbow grease. Cut the potato in half and cover it in dish soap with a sprinkle of salt or baking soda. These things are abrasive and so make it easier to get rid of the pesky rust.

Now simply rub the potato onto the rust until it comes away. When you’re done, make sure to rinse the knife and dry it thoroughly before storing it.

Salt and Lemon

Lemon is another food that contains acid so it’s ideal for treating rusty knives. Combine this with salt which is abrasive and you’ve got the perfect makeshift cleaning product.

You’ll need to apply salt to all of the rusted parts of the knife and then add the lemon juice over the top. Leave the solution to work for a couple of hours before you then scrub them using lemon rind. If this isn’t enough then it is possible to use steel wool for something a little more intense which is great if the rust is pretty stubborn.


Yep! Onions are just as effective when it comes to cleaning rust on stainless steel. Again, this is due to the presence of acid; sulfenic acid, in this case, which will as good as cause the rust to just come away without any effort from you.

When we say any effort, you will need to cut with the knife. Just take an onion and start slicing. Simply moving the blade through the vegetable should start to remove any rust.

Preventing Your Knives From Rusting in the First Place

While it is possible to remove rust from a stainless steel surface, it’s much better if you don’t have the problem in the first place. Here are some tips to help ensure that your knives stay in the best condition.

● Make sure that your knives are not exposed to moisture. When you have cleaned them, dry them properly before storing them and never leave them to soak in the sink.

● Some stainless steel knives can be cleaned in a dishwasher. While we wouldn’t recommend this, where possible, if you need to, then make sure you put the dishwasher on the shortest program.

● When cleaning your knives, it is best to use a mild soap with warm water. Use one cloth for cleaning and another to take away the soap. Use a third cloth or paper towel to dry the knife.

● Never use anything that contains chloride to clean your stainless steel knives.

● While steel wool will sometimes be the only thing that’ll get the rust off, you shouldn’t use this for general cleaning as it can scratch the metal, as can be seen on stainless steel pots or stainless steel utensils.

● Don’t store your knives together with cast iron items.

● Note that the minerals in tap water can be damaging to your knives.

● While you can oil a stainless steel knife, you don’t need to do this as much as you would if you were using a carbon steel blade. Generally speaking, you’ll only need to apply oil two or three times each year. Going over the top could do more harm than good.

● Keep your knives sharp by using a whetstone. For more information on knife sharpening, check out our guide.

Final Thoughts

Good knife care is essential if you want your kitchen blades to stand the test of time. However, there are some things that can cause stainless steel knives to rust. But that doesn’t mean that you should have to throw out your knives and buy new ones.

There are lots of things you already have in the house that will remove rust and have your stainless steel knives looking as good as new. This includes white vinegar, salt and lemon, baking soda and other things. Which you choose will depend on the severity of the rust but it’s always a good idea to protect your knives and prevent rust in the first place.


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