Why Do Safety Razor Blades Have Numbers (And Do They Matter?)

Have you ever purchased a razor blade with numbers on it? If so, you are probably wondering what they’re for. If these numbers are not there for fashion, then what could be the purpose and usefulness?

Some razor blades have numbers on either edge or the control neck. These are primarily for the manufacturer and can be helpful if there is a production issue. However, you can use them to track which side you’re using, allowing you to flip it and extend its life. In some cases, there may also be a number that lets you set the depth of your shave.

Keep reading to find out more about the origin of razor numbering and how to use these numbers correctly for your safety.

Why do some razor blades have numbers on them?

You bought a new razor blade and you found numbers on it. The first thing that comes to your mind is “what are these numbers for?” You checked the razor manual and asked your friends but still couldn’t find satisfactory answers to your question.

The answer will depend on the manufacturer of your razor, but it’s likely to mean nothing at all – at least to you. Many manufacturers will include numbers on the razors as a way of tracking in case there is a production issue.

Many users will use these numbers to track which side of the razor they have used and to ensure that they are flipping the blades consistently to extend their life.

Some manufacturers will include sequential numbers down the neck of the razor. These allow the user to set the depth of the blade and customize the quality of their shave.

Why do Derby Razors have numbers on them?

Derby razors have numbers 1 & 2 on both sides and 3 & 4 on the flip side. There are conflicting responses from shavers on the purpose and point of these numbers. The company has also come out to address the issue of blade numbering.

A company representative to me that “the numbers are there for quality control. They use them to check the calibrations on the sharpening systems in the factory.”

Despite this, many users I interviewed believe the numbers are meant for blade flipping while some said the numbers are meant for identification. Others side they use the numbering to keep track of the side they are using and immediately identify which side is irritating their face.

Why do Astra razors have numbers on them?

Similar to the Derby blade, Astra blades are also numbered from 1 to 4.

The company states that the numbers on their blades are for production and quality control purposes and do not affect the shaving experience of the shavers.

However, shavers feel the numbers are meant to ensure that you insert the blade properly in the razor. Also, some think the numbers are there for you to monitor which side you are using for shaving.

Why do some razors have numbers on their neck?

There are few razors in the market with numbers on their neck. One of them is the popular Merkur FUTUR razor which is numbered from 1 to 7.

Many users are confused by this numbering but here is what the company has to say: “the numbers on the neck of the razor are dial controls that allow you to control your shaving experience and fine-tune the closeness of the shave.”

Generally, the higher the number, the closer and deeper the shave. This razor is closest at 7 and is not recommended for beginners as it may cause cuts and injuries. 1 is the furthest and recommended for new shavers.

Some users reported that razors with this kind of numbering are too aggressive. However, I recommend that you keep it low as a first-time user and increase the numbering as you grow more comfortable.

How do you identify and use the numbers on the edges/sides of a razor?

Identifying the numbers on blades is not as difficult as you think. Once you can identify the numbers, it will be easy for you to put them into use.

Numbers are written on the sides/edges of razor blades. Especially when you buy the Astra or Derby razors, you will easily locate the numbers. However, if you purchase other brands, you may want to thoroughly check the sides to see if it is numbered.

There are numbers printed on the blades in the corners, a 1 and 2 on one side, and a 3 and 4 on the other side.

If your razor has numbers on it, there are several ways to use them to your benefit:

  • Monitor your shave
  • Dual usage
  • Multiple uses

Monitor your shave

With numbers on the sides of the blade, you can easily monitor which side you are using for the shave.

This will enable you to keep track of the stats and easily switch to another side when one becomes blunt.

Dual usage

If someone decides to share a blade (which is not always recommended) with you, you can easily use different parts with the help of the numbers on them.

This could be handy during a journey or when blades are scarce.

One blade – multiple uses

You can also use a single blade for multiple tasks without mix-up.

For instance, you can assign 1 for the face, 2 for the armpit, 3 for the chest, and 4 for other areas.

How do you use the numbers on the control neck of razors?

Numbers on the neck of the razor serve as a control.

They help you to choose the closeness of the shave. The higher the number, the closer the shave.

You should start with the lowest if you are using the razor for the first time. You can then adjust it to get the perfect settings for yourself. Ideally, setting the number between 3 and 5 will help you get the best shave.