August 19, 2021 2 min read

What is the Rockwell Hardness scale and how does it work?

You’ve probably seen different knife makers describe their steel with something called Rockwell C Hardness. We do it too. But what is Rockwell hardness and how does it measure the quality of the steel? Let us explain!

The Rockwell C hardness scale

The Rockwell C hardness scale is a way of measuring how resistant and hard a metal is. To measure the hardness in each knife or axe, engineers use the Rockwell C testing process to calculate its strength. It is a measuring system that is industry standard. Knife makers all over the world use it to estimate the characteristics of their metal and steel.


The higher the number on the scale, the harder the metal and steel. But how does it work? The short explanation is that an indenter is pressed into the metal surface under a given load. Depending on the depth of the indentation a hardness number is calculated. It’s difficult to explain, but if you look at the illustration below it might be easier to understand how it works.


Picture of Rockwell hardness scale

The Roselli Steel

Like said, most knives range between 45 HRC to 60 HRC. Our own UHC (Ultra High Carbon) steel measures around 62-63 HRC. Heimo Roselli’s years of refining forging techniques and studying metals led to a very particular smelting process and work formula — which to this day is a secret kept between Heimo and his men at the Roselli workshop in Harmoinen.


The Roselli UHC steel has taken us decades to perfect and with its long lasting sharpness and unique characteristics shown in our UHC (Ultra High Carbon) models measuring around 62-63 HRC — has been proven by knife enthusiasts all over the world.


Roselli knife blade in the making


Soft vs hard steel

There are both pros and cons to hard and soft steel, and different purposes for different kinds of steel. We made a guide to help you sort out what characteristics you’d want and need for your knife, depending on what you’re going to use it for. Read our blog post: What knife do I use for what purpose?


Our Carbon Steel Knives

Our standard carbon steel with 0,8% carbon is anything but standard. This steel measures 60 HRC and is our most trusted and used. Hard, durable and reliable - it is made to get the work done.


Our UHC (Ultra High Carbon) Steel Knives

Our own Ultra High Carbon (UHC) steel contains 1.8 - 2.0 % carbon. This unique Roselli steel measures around 62-63 HRC. This level of strength makes an extreme sharpness possible, and an edge which will stay sharp for a very very long time.


Roselli steel in the making


If you’re curious about the differences between soft and hard steel you can read more about our UHC (Ultra High Carbon) steel and Carbon steel in the blog post: Chipping - soft vs hard steel


Back to our other blog posts


Also in Blog

Unlock the secret to razor-sharp knives!
Unlock the secret to razor-sharp knives!

April 05, 2024 2 min read

We often receive the question from our customers about the sharpening angles we at Roselli use at the factory when sharpening our knives – and of course, we are happy to share that information so that you can easily sharpen your knives at home.
Read More
How to care for your kitchen knife in carbon steel
How to care for your kitchen knife in carbon steel

February 22, 2024 2 min read

If you've chosen a kitchen knife made from carbon steel, you've opted for exceptional sharpness, durability, and performance. However, to ensure your knife retains its quality and continues to serve you well for years to come, proper care and maintenance are essential.
Read More
The perfect guide on how to choose the perfect Roselli kitchen knife
Discover your perfect Roselli kitchen knife

February 15, 2024 4 min read

Choosing the right kitchen knife amidst a sea of options can be daunting. Allow us to guide you through Roselli's kitchen collection. Each blade boasts its unique attributes and strengths, tailored to meet various culinary needs. Join us as we explore these exceptional knives, designed to inspire your culinary creativity.
Read More