Can you shave with a knife? [Full guide]

When shaving a beard does it get any more masculine than shaving with a knife. It’s kind of silly in practice but there are so many knife enthusiasts that describe their sharpening as razor-sharp that it is only natural that people want to see if you can actually shave with a knife. Knives and razors are inherently different because they are primarily used for different purposes. Razor blades are used for removing hair from the skin whilst knives are used for cutting up meat and other edible goods. In this article, we will have a look to see if you can shape with a knife, how you do it, and the dangers of using a knife to shave.

You can shave with a knife, but it will be very different from shaving with a razor. The angles on the edge of the blade are different between knives and razor blades and you may have to apply extra pressure to shape with a knife which could end up damaging your skin.

Razors and knives are very different beasts. You can get a knife to become razor-sharp but cutting anything thicker than the most delicate of hairs can easily damage the sharp edge of the knife. If you damage the cutting-edge of the knife you are going to have to apply more pressure, and you run the risk of scratching up your face with micro scratches which can cause irritation and infection.

Razors and knifes are very different

Despite the fact that you can get a knife to become razor-sharp the actual razor blade and knife are very different.

Both razor blades and knives can dull through constant use. In a recent study by scientists at MIT showed that despite the fact that steel is 50 times harder than human hair it can still chip away the edge of metal razors.

The constant action of cutting a hair can perform the cutting blade in a more complex way than simply wearing down the edge over time. Even a single strand of cut hair can cause the edge of the blade to chip under specific trimming conditions.

The chips in the razor blade were caused when the hair was free to bend during cutting.

When the hair was cut perpendicular to the blade it did not cause any damage. Given the wild and curly nature of beard hairs it is very unlikely that you will always be cutting perfectly perpendicular to the blade.

This study shows that even the hardest of materials – stainless steel coated in carbon or other composite’s – can still be damaged by the much softer beard hairs. This is compounded by use and the more you use them the more likely the stress chipping at the cutting surface will happen.

The reason razor blades stay so sharp is that they are incredibly thin and you can get them parallel to the surface of your skin and perpendicular to the hair being cut. This causes the blade to become less damaged while cutting.

Knives are primarily meant for cutting up meat and vegetables or chopping down wood and whittling. Because so much force is put on a knife, they are incredibly thick to support the cutting edge and strong forces applied during use.

This means that when you shave with a knife it is very hard to get the cutting blade perpendicular to the hair that is cutting. Resulting in more damage to the edge of the blade and a worse cutting experience.

This doesn’t mean that it doesn’t work – it’s just much more dangerous for the skin and the face that using a razor blade. Here is a YouTube video which shows how you can shave with a knife.

You’ll notice that it is much easier to neck the skin due to the shape of the knife. Many nights have a point for stabbing actions which can easily concentrate the force onto your face and cause more next than if you were to use a razor blade. Razor blades are typically flat and held in place with a handle which means that you cannot concentrate the force onto a single point. This means they are typically much safer to use on your face.

If you want to shave with a knife here are the steps for doing so safely.

How to shave with a knife

It may not be your everyday activity but sometimes I just feel like shaving my beard and the lines of my beard with a knife. I don’t know whether it is ego, primitive drive, or just novelty which makes me have that desire.

If you are absolutely certain that you want to take all of the risks associated with shaving with a knife here are the steps for doing it efficiently and safely.

Can you shave with a knife

Sharpen the knife!

The very first thing is to make sure that you have the sharpest knife possible. Here are the steps for getting your knife as sharp as humanly possible so that it will cut the hairs cleanly.

  • Assess the blade quality – when you run your fingernail over the edge of the blade or you look at it from the side on you can see many small breaks and chips in the edge of the knife. The depth of the chips that have been taken out of the cutting-edge will determine how much metal you need to take off the entire edge to keep the same shape.
  • De-stressing – the steel at the very edge of your knife is weak and is ruined from the use. Take the knife and draw it over the sharpening stone to blunt the age but expose the virgin steel. Use a very light pressure.
  • Determine your sharpening angle – starting at about 15° of angle determine if you want your knife edge to be a shallow or steep angle. For cutting your hair you want to stay around 15° or slightly less.
  • Sharpen – use a sharpening stone to sharpen the edge to a point. Make long sweeping strokes using as much of the surface area is a star as possible and working in different sections if necessary. Applied relatively light pressure and use even strokes on both sides of a 220 to 350 grit to keep the shape of the knife the same
  • apply a micro bevel – once the primary edge has been created you have to apply a micro bevel. This is the part of the edge that is actually doing the cutting. Use strokes that are slightly higher angles than the one used to create the edge bevel.
  • Stropping – stropping the edge is the final step. It will hone an edge and align the teeth created by the scratches from the stone. This can be done with a flat piece of cardboard newspaper blue jeans or a leather belt. Instead of using leading strokes, you will drag the edge backwards over the strop to create a honed edge.

Using this simple technique, you will be able to produce very sharp blades and, with practice, and patience you will be able to sharpen even the dullest of blades.

If it hasn’t quite worked out for you trial different pressures and angles until you find one that works.

Consider using DMT sharpeners as they work for a wide variety of materials and knives.

Lather up

If you are using a knife instead of a razor you will need to prepare the skin by using a good quality lather. Also, you should consider warming up the hairs with a hot flannel or jump in the shower before shaving. You want to open your pause as much as possible and soften the hairs. Hair absorbs water and become significantly weaker – making it much easier to cut with your knife.

Hold the knife at an angle to your face

This step requires a lot of practice and involves a lot of trial and error and concentration. If you’re using a knife you cannot simply use the same technique you would with a razor blade. Aim to hold your knife at a 30° angle to your face to allow the blade to smoothly cut through the hair. The thickness of the blade will determine how comfortable this is to do.

This angle will prevent the blade from tearing the hairs which can happen if the angle is too flat. If it is to upright you risk cutting through your skin also.

Practice with this angle until you find something that is removing the hairs but not causing you any discomfort whilst also being efficient at shaving.

Hold the skin taut

Before you start stroking the knife across your entire face you will need to hold the skin so that it is a little bit more taut than usual. This will stop the skin from dragging which increases the risk of pulling or cutting the skin.

This can get relatively confusing as you need to navigate your face with a hand to pull the skin taut whilst also dragging the knife over at a predictable angle.

Some areas of the face are a lot more challenging than others such as the jaw lines, moustache areas, and chin. You can easily nick these areas and cause bleeding.

Slow predictable movements and light pressure will minimise the risk of cutting your skin.

Can you shave with a knife

Less strokes = better

It will take time to perfect the action of shaving with a knife but you want to aim to shave as efficiently as possible with as few a strokes possible to reduce irritation.

Start by shaving downwards in one direction to make sure that you are applying even pressure across your face. Once you have finished shaving downwards you can then decide whether or not you need to go for a second pass which you should do perpendicular to the growth – against or across the grain of growth.

After care

after you are happy that you have got all of the hairs you can with your knife you need to continue with a post shave care routine. Hold a cold flannel on your skin and splash your face with cold water to close the pores. You must apply plenty of moisturiser or post shave cream to look after the skin and return it to its pre-shave condition.

Is shaving with a knife better?

I think the answer to this question is that shaving with a knife is not better. That is because it is very difficult to hone a knife to a sharp edge like a razor. The bevel angle is different, the grind angle is different, and the knife does not have a built-in honing angle guide like a razor does.

Shaving with a knife is awkward because of the length and it doesn’t do as good a job as a blade that is specifically designed for cutting and maintaining hairs.

A knife can easily be made to shave hair with a 1000 gritstone but for a razor to shave close and comfortably the edge must be taken to a minimum of 8000 grit. A good razor’s edge would also be only about 17°.

The risk of cutting yourself is much higher and here are a few other dangers of shaving with a knife that I have collected from around the Internet from people’s first-hand experience.

Dangers of shaving with a knife

There are many dangers of shaving with a knife which include cutting up your face, inadvertently cutting something due to the length of the knife, chipping the knife’s blade, irritation and ingrown hairs after using a knife.

Cutting up your face

Obviously, one of the first dangers is that you are increasing the risk of cutting up your face in a significant way. The shape of the knife blade will likely come to a point. This point concentrates all of the force of the knife into your skin. If you watch people shaving with a knife this is where the majority of the next come from.

When you shave with the full length of the knife the pressure that you apply is averaged out over the entire blade. The smallest lapse of concentration can concentrate that force into the curve or tip of the knife causing you to cut into your skin.

Length of the knife

The length of the knife is also a huge concern. Your face is full of multiple angles and surfaces that need to be cut precisely. Trying to use a blade longer than a regular razor blade means that you have to manoeuvre the blade of the knife around your nose, Adam’s apple, shoulders, ears, and anything else that kind of sticks out from your head.

There are a few reasons why the blade of a razor is only a few centimetres long and the primary reason is that it is the most comfortable length for manoeuvring around your face to cut your hair.

Chipping the blade

Another issue is that, as we have seen above, the blade is likely to become damaged even when cutting hair. Beard hair is relatively thick and coarse and using a hand blade can easily cut into the cutting edge. If you want to know more about why beard hairs are so thick check out my answers from science in this article – click here.

Why are beard hairs so thick

Irritation

Using a knife is a relatively inefficient way to remove hairs from your face. This means that you are more likely to go over the same spot multiple times.

If you look at anyone, on YouTube, who has used a knife to shave they are typically very red after they have finished. This is because they have not perfected the angle, the blade is likely to dull, and they have applied too much pressure while shaving.not an ideal situation for leaving your skin in the best condition possible. It may take a full couple of days for the irritation to subside due to the micro abrasions of the blade scratching against the skin.

Ingrown hairs

Lastly, it is very hard to get a predictable cutting angle with a knife. The flexibility that the person has two change the angle means that some areas will be cut at a shallower angle than others. Tearing out the hair if it is too shallow or simply not cutting efficiently if it is too steep means that it is likely that you will have ingrown hairs at some point on your face due to the cutting angle.

Can you shave with a pocket knife?

You can absolutely shave with a pocketknife. As long as you get the cutting angle correct and fun the blade to as sharp as possible you can use it to cut facial hair. However, the blade will dull quickly and it will not give you as good as shave as a razor blade.

Summary

In this article, we have gone over everything you need to know about shaving with a knife. Ultimately, it may be something that you want to try but is not practical for everyday shaving.

There are a number of downsides such as continuous maintenance of the knife, a significant increase in nicks and cuts as well as the reproducibility of the shave across the entire face.

I recommend that if you want to shave with a knife you take it slowly and you practice on the cheek area of your face so that you can vary the angle into you find the perfect cutting angle. It may be just a novelty for you but be careful and go slowly over your face.

The Author


Andy Stapleton

Andy is a writer and YouTuber with a PhD in science. He has written and/or produced videos for Science Alert, COSMOS magazine, and Australia's Science Channel among others. He is an avid beard grower and after many years of growing and trialing different beard styles, he started this blog to share the tips, tricks, and science that he has learned along the way!