Advantages of CBN inserts for processing gray cast iron

CBN inserts, the main application areas are high hardness cast iron / hard steel and other fields, and ordinary gray cast iron 

is also a field in which CBN tools are often involved. Especially for roughing and CNC machining, CBN inserts are more widely 

used.

Gray cast iron has low hardness and can be processed by traditional carbide tools. But why choose a CBN inserts that is more 

expensive than traditional carbide tools? The reasons are as follows:

(1) Gray cast iron material is mainly used in machine tools, automobiles and other industries. Most of the parts are mass-produced, 

which requires high production efficiency. Although traditional carbide tools can also process gray cast iron, the processing efficiency 

is low and only suitable for small batch production. , or occasionally processing gray cast iron parts.

(2)Nowadays, enterprises that produce high-volume gray cast iron parts mainly use CNC lathe processing.Many people know that 

traditional tools can't cut at high speed. When the maximum line speed (350m/min) is exceeded, severe wear willoccur, which will 

affect production efficiency and the surface quality of the workpiece.

(3) CBN inserts have high hardness and good wear resistance. The precision gray cast iron can achieve a line speed of 1000m/min, 

so it is suitable for mass production of gray cast iron parts with CNC lathes. And can guarantee high requirements such as smoothness

and flatness.



                           

Halnn Superhard, has been the most well-known tool brand in the field of hard material processing for more than ten years. Moreover, 

with the long-term cultivation and accumulated technical strength and the most advanced technology development capability, the 

concept of “ solid PCBN inserts ” for rough processing was first proposed in China, and it is suitable for the cutting requirements of 

modern “high speed, precision machining”. There is a good tool material in the field of gray cast iron.

According to the processing steps and precision requirements of gray cast iron, Halnn  has developed three CBN grade inserts. 

The following is a brief introduction to its performance and advantages.

Classified according to the processing procedure:

(1) Roughing process, choose the solid CBN inserts----BN-S30 CBN grade, the advantage is: large cutting depth(ap), good wear 

resistance, long service life;


                                      

(2) Semi-finishing: Select the BN-S300 CBN grade inserts (the appearance of the blade is the same as the BN-S30 CBN grade inserts).

The advantage is: high sharpness, high precision and long tool life;

(3) Finishing: The brazed CBN inserts---BN-K20 CBN grade is selected. The advantages are: high cutting speed(Vc), more cutting edge, 

and more flexible clamping method.

Not only that, Halnn has also developed a tool that can process gray cast iron parts at the same time. Take the brake disc as an 

example. The original processing procedure is to change the direction and then process the other side after processing one side.

With double-cutter clamping tool, it can be clamped at one time, and the upper and lower end faces are processed at the same time, 

which not only reduces the production time by 50%, but also maintains better flatness and higher efficiency.

As shown in the figure, the processing effect of Halnn solid CBN inserts---BN-S300 CBN grade finishing gray cast iron brake 

disc end face.

Machining workpiece: brake disc(GG25)

Processing: Finishing

Processing part: end face (brake surface)

Tool number: BN-S300 SCGN090408

Machining method: double CBN inserts processing end face at the same time

Cutting parameters: Cutting depth (ap)=0.25mm, 

Feed rate(Fr)=0.2mm/r, 

Cutting speed(Vc)=800m/min

Processing method: dry cutting

 
Processing effect: compared with coated carbide inserts, the results are as follows

Tool material

Inserts type

Line speed

Single edge life