SUMIBORON/Coated SUMIBORON
K Guidance for SUMIBORON Grades
Cast Iron
● Advantages of using CBN
CAST IRON MACHINING Following chart shows advantages of using CBN in cast iron machining compared with
conventional tool, such as carbide, cermet or ceramics.
SUMIBORON has longer tool life than conventional tools in high speed machining and brings
higher efficiency and superior precision.
High Speed Machining High Speed Machining High Precision Machining
Gray Cast Iron Ductile Cast Iron
BNS800 500
Cutting Speed vC(m/min) 1,000 BN7000 Cutting Speed vC(m/min) BNX10 Tolerance Ceramic
BN500 BNS800 Coated carbide
BN7000 Cermet
BNC500 BNC500
500 200
Ceramic BN7000
200 Ceramic Coated carbide Good←
Coated carbide Cermet
Cermet
1 10 20 1 10 0.4 0.8 1.6 3.2
Tool Life Tool Life Good← Surface Roughness Ra (μm)
■ Recommended Grade Grade Binder CBN Conten(t %) Grain Size(μm) Hardness(GPa) TRS(GPa) Coating Thickness(μm) Characteristics
BNS800 AI Compound 85 to 90 8 39 to 42 0.95 to 1.10 ̶ ̶ Grade with 100% solid CBN structure
and excellent thermal shock resistance.
Uncoated Exhibits improved wear and fracture
BN7000 Co Compound 90 to 95 2 41 to 44 1.30 to 1.40 ̶ ̶ resistance in cutting of cast iron and
exotic alloys.
Optimized for cast iron cutting.
BN500 TiC 65 to 70 6 32 to 34 1.00 to 1.10 ̶ ̶ Provides superior wear and fracture
resistance.
Coated BNC500 Suitable for machining of hard-to-cut
(Ductile Cast Iron) TiC 60 to 65 4 32 to 34 1.00 to 1.10 TiAIN 2 cast iron thanks to the highly wear-
resistant substrate and coating.
* Refer to pages L9 and L10 for machining of sintered components, rolls, hard facing alloys and heat resistive alloys.
■ Application Range