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NTK Cutting Tools

BK310 | BK320 | BK350

Ductile & Cast Iron, Sindered Power metal

High-Quality Surface Machining – CBN
Home / Cast Iron - Grade / BK310 | BK320 | BK350

The New Era of NTK CBN Grades

High CBN content provides excellent wear resistance and long tool life
Features
  • Uncoated grades offering sharp cutting edges and wear resistance in cast iron and sintered alloys
  • Optimized CBN composition, advanced edge preparations, and a cost-effective double-sided brazed insert design that maximizes value per cutter.
  • Maintain surface quality even in high-speed and heavy-load conditions
Grade map
Cast iron
Max 1200m/min 4000SFM
Finishing
↑High




SPEED
BK310
BK320
Continuous Light Interrupt Heavy interrupt
Sintered powder metal
Max 300m/min 1000SFM
Finishing
↑High



SPEED
BK310
0.1 .004 0.3 .012 0.5 .020
ap (mm) (inch)
Ductile
Max 500m/min 1500SFM
Finishing
↑High



SPEED
BK350
0.1 .004 0.5 .020 1.0 .040
ap (mm) (inch)
Grade Comparison Table
NEW OLD
BK310 B30
BK320 B23
BK350 B52

Cast iron – Finishing

Sintered powder metal

Ductile cast iron – Finishing

Uncoated CBN　BK310 / BK320

High CBN content provides stable wear resistance in high-speed turning of Gray cast iron and sintered alloys.
Fine particle size provides excellent edge sharpness and is effective in suppressing burrs.

BK310 Competitor

Gray cast iron (FC300)
vc = 500m/min 1600 SFM , f = 0.3mm/rev .012 IPR , ap = 0.3mm .012” DOC ,
After processing 3Km 120000”

Uncoated CBN　BK350

General-purpose material with excellent wear resistance and chipping resistance compared to ductile cast iron for continuous to heavy interrupted use.

BK350 Competitor

Ductile cast iron (FCD600)
vc = 300m/min 1000 SFM , f = 0.1mm/rev .004 IPR , ap = 0.2mm .008” DOC ,
After processing 4Km 160000”

Cutting edge preparation according to processing purposes

←　Sharpness

Toughness　→

- - - Scroll the table - - -
ISO Work material Coolant Grade vc (m/min) (SFM) ap (mm) (inch) f (mm/rev) (IPR)
Cast Iron Finish Turning WET BK310 400 ~ 1200 1300 ~ 4000 ~ 2.0 ~ .080 ~ 0.5 ~ .020
BK320 400 ~ 1000 1300 ~ 3300 ~ 2.0 ~ .080 ~ 0.5 ~ .020
Sinterd alloy Finish Turning BK310 40 ~ 300 130 ~ 1000 ~ 0.5 ~ .020 ~ 0.5 ~ .020
Ductile Finish Turning DRY BK350 100 ~ 450 300 ~ 1500 ~ 1.0 ~ .040 ~ 0.4 ~ .016
Agriculture component
Insert :
TNGA160408PHT01020
Material :
Gray cast iron (FC250)
Cutting speed :
700 m/min 2300 SFM
Feed :
0.1 mm/rev .004 IPR
DOC :
0.2 mm .008 inch
Coolant :
WET
BK310
150 pcs / corner
Competitor’s CBN
100 pcs / corner

Conventional CBN would experience chattering at the corners and reach the end of their tool life, but BK310 maintains its sharpness and achieved 1.5 times longer tool life.

Machinery component
Insert :
CNGA120408PQT01020
Material :
Ductile cast iron (FCD450)
Cutting speed :
400 m/min 1300 SFM
Feed :
0.05 mm/rev .002 IPR
DOC :
0.5 mm .020 inch
Coolant :
WET
BK350
100 pcs / corner
Competitor’s CBN
50 pcs / corner

Conventional CBN develop burrs in the hole and reach the end of its tool life, but BK350 maintains its sharpness and achieves twice the tool life.

View more BK310 reports
View more BK350 reports
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For more information about this product, visit our online e-catalog, or download the catalog/product report

BK310 eCatalog (mm)
BK310 eCatalog (in)
BK320 eCatalog (mm)
BK320 eCatalog (in)
BK350 eCatalog (mm)
BK350 eCatalog (in)
Catalog
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