
hard cast iron. Long tool life with high-speed finishing of grey cast iron. In 1977, Sumitomo Electric Hardmetal successfully developed a revolutionary CBN sintered tool - SUMIBORON. The main component in SUMIBORON is Cubic Boron Nitride with a special ceramic binder sintered under super high pressure and temperature. As compared to other conventional tool materials, CBN has higher hardness and excellent heat resistance. With these distinct characteristics, SUMIBORON can perform machining of hardened steel, high hardness cast iron and exotic metals where previously only grinding was done. Furthermore, excellent efficiency and longer tool life can also be achieved from high speed machining of cast irons.
Classifications Structure CBN Content Hardness (GPa) Grades Application Characteristics
| 44 High | Carbide | High carbon content. Structure consists of | |
| BN700 | |||
| Mainly CBN | BN7000 | Chilled cast iron | strongly fused CBN grains. |
| grains fused | BN7500 | Ni-Hard cast iron | Suited to cutting cast iron, heat-resistant |
| together | BNS800 | Heat-resistant alloy, Cast iron | alloy, ultra-hard alloy, and other hard |
| Sintered ferrous alloy | materials. | ||
| BNC500,* | |||
| BN1000, BN2000, | Alloy steel | CBN grains are fused together strongly with | |
| Mainly CBN | BN350,* BNX10, | ||
| grains held | Case hardened steel | a special ceramic binder. | |
| BNX20, BNX25, | Carbon tool steels | Strong CBN binding force gives superior wear | |
| together with | |||
| a binder | BNC2010, BNC2020 | Bearing steel, Die steel | resistance and toughness when cutting hardened |
| BNC100, BNC160, | Ductile cast iron | steel and cast iron. | |
| 21 Low BNC200, BNC300 | |||
| *BNC500 can also be used with cast iron, | |||
| while BN350 can also be used with sintered ferrous alloys. | |||
| Grade Range Map |
Class Series Finishing ~ Light Cutting Medium Cutting Rough ~ Heavy Cutting
Classification H01 H10 H20 H30
BNC2010 BNC2020 Coated SUMIBORON BNC100
BNC160 BNC200 BNC300 BNX10, BN1000 Uncoted BN2000 SUMIBORON BNX20 BNX25, BN350
| Classification | 01 | 10 | 20 | 30 |
| BN7000 BN700, | ||||
| Uncoted | ||||
| SUMIBORON | ||||
| BN7500 | ||||
| Classification | K01 | K10 | K20 | K30 |
Coated BNC500 SUMIBORON BN7000, BN700 Uncoted BN7500
SUMIBORON BNS800