Hard turning with CBN - Finish Machining

Through hardened En31 Bearing Steel Machining

For finish-machining of hardened steels and certain softer ferrous materials:

Surface and through hardened steels

High speed steels

Bearing steels

Hot - work die steels

Cold - work tool steels

Grey and chilled cast iron

Sintered Irons

CBN cutting tools machine hardened steels with apparent ease because, using relatively high surface speeds, heat is generated at the point of cutting so the PCBN tool cuts locally softened material. The heat is carried away by the swarf, which becomes brittle and harmless, and the PCBN tool, which has a high co-efficient of thermal conductivity. If a light cut is required, however, a tool with a high CBN content conducts too much heat away from the shear zone and the conditions for efficient machining cannot be achieved.

DR-50 & DR-50N have a low CBN content and the individual CBN particles are isolated within a ceramic matrix. This gives the materials a lower thermal conductivity and greater wear resistance in finish cutting operations.

Low CBN tools can therefore keep sufficient heat at the cutting point to enable the optimum cutting conditions to be achieved when a light cut is taken. In most cases, even when very light cuts are required, low CBN tools employ negative rake geometry to provide a strong edge. Due to the nature of cutting, however, cutting forces are still very small. Low CBN can be used to provide a productive and cost effective alternative to grinding.Tolerances achieved are comparable but machining time can be dramatically reduced.

DR-50 has a low CBN content and is designed for finishing and semi-finishing applications where grinding with conventional abrasives proves time consuming or difficult. DR-450 is tougher and performs well over severe interruptions.

UK Customers
CBN Inserts for finishing

US Customers
CBN Inserts for finishing

Machines for hardturning

Thanks to David Richards Engineering Limited