blender blades

This article covers how to sharpen blender blades, as well as when and why (or why not) you might want to do so.

Be sure to read all the way to the end for some FAQs, common misconceptions, and things to look out for when it comes to keeping your blender blades sharp.

Let’s get into it!

Types of Blender Blades

Blender blades are usually either:

  • 4 angled blades (2 up, 2 down) at the bottom of the blending container (i.e. what you find in most standard blenders)
  • 6 horizontal blades assembled along a vertical post in the centre of the blending container (ex: Ninja blender blades)
  • 1 blunt blade (fastened in the middle to create 2 “blades” with upturned ends) at the bottom of the blending container (ex: Blendtec blender blades)
  • 2 horizontal blades at the bottom of the blending container (mostly bullet blenders, or special blades for grinding)

It is important to know what kind of blades your blender has because some blades will simply not need or allow for sharpening – the “blunt blade” found in some blenders being the obvious one. (More on this below).

Why Are Blender Blades Not Sharp?

If you take a close look at your blender’s blades, you’ll probably realize that they are not all that sharp. Or, in some cases, they might be completely dull chunks of metal without the sharpness that we typically associate with a “blade”.

There are a few different reasons why your blender blades may not be sharp…

First of all, as mentioned above, there are all sorts of different blender blade designs. Not all blender blades are made to be sharp. For example, Blendtec blender blades are intentionally designed to be blunt.

When it comes to blending ability, the power of the blender matters more than the blade sharpness. A high-end blender, such as a Blendtec blender, has a powerful enough motor to blend through any ingredient using the sheer speed of the blades.

Because of this, with most blenders, you’ll notice that even the sharp blender blades aren’t that sharp (like a knife would be, for example). While sharpness and thinness of the blades can help in some cases, they are not that important in high-end blenders where the blades are able to move at extremely high speeds.

Most blender blades found in standard household blenders have bevelled/slanted edges to give them some sharpness, but again, they probably won’t look the same as a knife blade which typically has a very thin, long, and sharp edge.

However, there are some blenders that do have more knife-like blades that lay more horizontal and are thinner and sharper (kind of like food processor blades). These are usually found in smaller, specialized blending cups, such as for grinding dry ingredients with a bullet blender.

Another reason your blender blades may not be sharp, is that they have simply become dull with use.

Your blender blades may have started out sharp, but the edges may gradually dull over time with use, especially with improper use. Blending hard ingredients with little or no liquid may contribute to blade dulling.

Also, excessive dishwasher use, or improper cleaning (using abrasive materials and soaps) can dull blades. And sometimes, your blades just need a good scrub to get rid of any lingering residues and grime and expose more of the blade edges! See this How to Clean a Blender guide for detailed methods of properly cleaning your blender.

If you notice your blender blades have become dull and you want to restore them to their original sharpness, here are some sharpening methods you can try…

How to Sharpen Blender Blades

Important note: Always handle blender blades with extreme care, before, during, and after sharpening.

Like most kitchen knives, blender blades are made of stainless steel. This means they can be sharpened in much the same way.

There are a few different knife sharpening tools you can choose from, depending on what kind of blender blades you have.

The angles, curvature, and positioning of the blades will help you determine if and how you might want to sharpen them, and what tools to use.

Let’s go over some of the best sharpening methods and tools…

How to Sharpen Blender Blades With a Stone

The best way to sharpen a stainless steel blade, is with a whetstone.

However, note that the only blender blades that can be sharpened with a whetstone are flat, thin, and sharp blender blades. This method won’t work with blender blades that don’t resemble a knife’s blade.

Also note: In order to be able to sharpen blender blades with a stone, the blades have to be able to detach from the rest of the blender, and each individual blade needs to be accessible in order to be individually sharpened.

These are the general steps you can follow to sharpen blender blades with a stone:

  1. Carefully detach the blades from the blender (make sure you know how it goes back together!).
  2. Clean the blades thoroughly with soap and water and a non-abrasive sponge/cloth.
  3. Prep the whetstone – with water or oil, depending on the stone.
  4. Position the blade to be sharpened at a slight angle from the horizontal, along the stone.
  5. Draw the blade horizontally across the stone in one direction, maintaining the same angle.
  6. Repeat on the other side of the blade. You can test the blade on a paper or tomato to see if it is sharp.
  7. Clean the blade thoroughly and carefully re-assemble the blades in the blender.

Using a sharpening stone takes practice to get it right, so it is a good idea to practice on an inexpensive knife first. It’s also a good idea to follow a video tutorial.

If you’re not up for sharpening your blender blades yourself at home, or you can’t get your hands on a whetstone, you can always get them sharpened by an experienced sharpener. Or try one of these simpler methods below…

How to Sharpen Blender Blades With a Knife Sharpener

The most convenient and most commonly effective way to sharpen blender blades is with a basic kitchen knife sharpener, such as a file sharpener (the slightly rough metal stick that you manually move along the blade) or a pull-through knife sharpener (the sharpener with V-shaped blades that you slide the blade through).

Let’s go over each of these tools/methods…

File sharpener:

The main advantage of a file is that it can work with most blender blades, regardless of the positioning or angles of the blades. You don’t have to detach each individual blade (although you definitely still have to remove the blade assembly from the rest of the blender), and you can maneuver around the contours of the different blades easily with this small tool.

These are the general steps you can follow to sharpen blender blades with a file sharpener:

  1. Carefully detach the blades from the blender (make sure you know how it goes back together!).
  2. Clean the blades thoroughly with soap and water and a non-abrasive sponge/cloth.
  3. Align the file with the bevel/slant of the blade edge. Draw the file across the bevel, maintaining and even and parallel position. Repeat the motion until sharp. You can test the blade on a paper or tomato to see if it is sharp.
  4. Clean the blade thoroughly and carefully re-assemble the blades in the blender.

Pull-through sharpener:

This one is more like the whetstone, where you can only use it with flat, knife-like blender blades (ex: Ninja 6-blade assembly).

These are the general steps you can follow to sharpen blender blades with a pull-through sharpener:

  1. Carefully detach the blades from the blender (make sure you know how it goes back together!).
  2. Clean the blades thoroughly with soap and water and a non-abrasive sponge/cloth.
  3. Draw each blade individually through the V-shaped sharpener as you would a knife, using light but even pressure. Repeat the motion until sharp. You can test the blade on a paper or tomato to see if it is sharp.
  4. Clean the blade thoroughly and carefully re-assemble the blades in the blender.

How to Sharpen Blender Blades Without a Stone or Knife Sharpener

There are a few other methods out there for sharpening blender blades without the need for a blade sharpener of any sort, or even the need to remove the blades from the blender. Namely, (1) blending eggshells and water, (2) blending raw, course salt, and (3) even blending aluminum foil is an option…

While these are some of the most commonly listed methods of sharpening blender blades out there, I have not tried any of these methods (mostly out of fear of damaging my blender).

My train of thought it that what causes blades to become dull in the first place is the uneven abrasion of abrasive foods against the edges of the blades. I figure that blending a bunch of eggshells/salt/aluminum foil would have the same effect.

On the other hand, perhaps if you blend long enough, you can maintain a consistent blending motion that gently abrases the blades to remove any unevenness/knicks/residues. I’m really not sure though, so for now I would not recommend these methods.

If you’ve tried any of these methods, please let me know in the comment section below! I’d love to know if these simple methods actually work (without harming the blades or the blender at all)!

Note: If you’re wondering about ice – if it can be used as a sharpening method as is also commonly suggested – I go over that in the FAQ below.

Blender Blades FAQ

How Often Should You Replace Your Blender Blade?

Blender blades should not need frequent replacing, or replacing at all for that matter.

Blender blades are made of tough steel and are generally meant to last the entire lifetime of the blender without significant wear-down. Even cheaper blenders will have durable blades – the rest of the blender is likely to breakdown long before the blades.

However, blender blades may get knicked, discoloured, or dullened over time with use.

How you use your blender, and how frequently you use it, does play a role in the condition of your blender blades. For example, blending ice or other hard/frozen/tough ingredients can be tough on the blades over time.

This is where sharpening can come in handy. Sharpening your blender blades can help keep them in top condition, or restore them to top condition, even with years and years of heavy use.

(Again, this is only relevant if you have sharp blender blades, not intentionally dull blender blades.)

So unless something is wrong with your blender blades out of the box, or if they somehow break or get warped, they should not need replacing.

So, how often should you sharpen your blender blades?

Blender blades do not have to be sharpened very often at all. Maybe once every one or two years, or when you start noticing that the blender is not getting through tougher ingredients.

Keep in mind though, that struggling to blend tough ingredients is most likely a result of the power of your blender as opposed to the sharpness of the blades.

Do Ice Cubes Damage Blender Blades? / Can you Sharpen Blender Blades With Ice?

Yes, ice cubes can damage blender blades over time.

But wait, can’t you sharpen blender blades with ice?

While it is sometimes said that you can sharpen blender blades with ice, I would definitely not recommend this. Blending ice actually causes the blades to dull over time. Especially with large cubes, the hard ice will hit the edges of the blades at all sorts of angles, hence causing the edges to dull and become slightly uneven or raggedy.

Many high-grade blenders are known for their competency in blending ice, and can definitely be used to blend ice or frozen ingredients without worry. But the proper way to do so is to ensure you include plenty of liquid and other ingredients alongside the ice to help soften the collision of the ice into the blades and thus reduce any dulling and harm to the blades.

In short, there is no reason that the blades would end up sharper from this experience of blending hard chunks of ice!


Blenders can have all sorts of different blades that vary in design and sharpness. Many blender blades cannot or should not be sharpened.

To sharpen dull blender blades that can be sharpened, try using a basic knife sharpener such as file or pull-through sharpener, or a whetstone, depending on what type of blades you have.

Other theoretical methods of blender blade sharpening include blending eggshells, salt, or aluminum foil. However, it is inconclusive whether or not these methods actually work (…or if they cause harm to your blender).

And finally, do not use ice to sharpen blender blades (it won’t work).

Let me know in the comments what method(s) you’ve tried for sharpening blender blades. I’m curious to know what has or hasn’t worked for you!

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Just Knives
11 months ago

Great article

11 months ago

Finally somebody who actually thinks about this before offering an answer. Appreciated. Those who recommend ice to sharpen probably think that pebbles would also work! Or sand, right? I don’t buy into anything abrasive working by just blending. Seems like the wear on the blades would be at all angles and not along the cutting bevel. Much more likely to dull them if anything.