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

The perfect survival guide with tips on how to camp in the cold
Surviving Guide: Discover Engin's winter camping secrets!

November 03, 2023 4 min read

Discover Engin's essential tips and expert guidance for a memorable autumn and winter camping experience. Learn how to stay warm, choose the perfect gear, and embrace the beauty of the changing seasons in this comprehensive camping guide.
Read More
Rosellis Finnish handmade outdoor knife, made by carbon steel.
Discover Juho 1: Only 6 exclusive pieces

October 12, 2023 2 min read

Limited edition: Blacksmith Juho's 6 exclusive knives
We at Roselli are passionate about creating products that are more than just tools - they are your loyal companions out in nature. We are therfore proud to introduce the 
Juho 1 Knife, which embodies our craftsmanship, our love of adventure and our commitment to sustainability. Discover now! 
Read More
Rosellis knife and axe guide for the summer
Unleash your inner adventurer this summer!

June 22, 2023 2 min read

Are you ready to embark on an extraordinary outdoor journey? With summer in full swing, it's time to gear up and make the most of your time in the wild. At Roselli, we're here to inspire and equip you for unforgettable experiences in bushcrafting, fishing, camping, and hiking. Let's dive into the exciting world of outdoor exploration and discover the perfect Roselli gear for each adventure.
Read More