SATURNINO FIORI CATE SRL
VAT No. and Tax Code 09754230010
Via Alcide De Gasperi,15 * 10024 MONCALIERI (TO) - ITALY
Tel. +39 011 18866055 - e-Mail: amministrazione@saturninofiori.com
CBN grades: how to choose the right one for each process
When it comes to CBN (Cubic Boron Nitride) tools, the real difference between a mediocre result and excellent machining does not lie only in the insert geometry.
It lies in the grade.
Each CBN grade is designed for a specific balance between:
- wear resistance
- toughness
- thermal stability
- behavior in continuous or interrupted cutting
Choosing the wrong grade means:
- sudden breakages
- accelerated wear
- non-compliant surface finish
- high cost per part
The logic of CBN grades
The key parameter is the CBN content within the material.
The higher the CBN percentage:
- the greater the resistance to abrasive wear
- the lower the impact toughness
The lower the percentage:
- the greater the resistance to chipping
- the better the surface finish
The three main CATE grades
We have developed a clear and rational range that covers all operating needs.
BX556 – Steel finishing (continuous cutting)
The ideal grade to obtain grinding-quality surfaces directly by turning.
✔ Perfect for:
- hardened steels >45 HRC
- continuous machining
- high speeds
✔ Advantages:
- excellent surface finish
- high process stability
- reduced cycle times
This is the grade to choose when the priority is part quality.
BX555 – Universal grade (interrupted cutting)
The best compromise between strength and tool life.
✔ Perfect for:
- hardened steels
- machining with interruptions
- conditions that are not perfectly stable
✔ Advantages:
- high toughness
- resistance to chipping
- great versatility
It is the most widely used grade when production reliability is needed.
BX558 – Cast irons and abrasive materials
The grade designed for the toughest conditions.
✔ Perfect for:
- gray and ductile cast iron
- sintered materials
- machining with high abrasiveness
- heavy interrupted cutting
✔ Advantages:
- maximum wear resistance
- stability even in the presence of impacts
- long tool life
This is the grade to choose when the problem is wear, not breakage.
How to choose the right grade
You can use this simple logic:
- Want a perfect finish → BX556
- Have interruptions → BX555
- Machining cast iron or abrasive materials → BX558
Why the grade makes the difference
Two apparently identical inserts can behave in completely different ways.
The reason lies in the internal structure:
- CBN percentage
- type of binder
- grain size
This is where true quality is born.
Need help choosing?
Every application is different.
We can help you:
- select the right grade
- define cutting parameters
- optimize tool life and tool cost
Contact us or discover the full range in our catalog.