Description

If you mean the blue diamond ball-nose cutter specifically for CNC stone cutting/carving, the product is generally called a vacuum-brazed diamond stone router ball-nose cutter. It is used for marble, granite, sandstone and other stone, particularly for 3D finishing/carving.

Recommended specifications

For a CNC router, common options are:

• 4 mm shank × 6 mm cutting diameter — general stone carving
• 6 mm shank × 6 mm cutting diameter — general stone carving
• 8 mm shank × 8 mm cutting diameter — heavier work
• 10 mm shank × 10 mm cutting diameter — larger/stronger machines
• Vacuum brazed diamond — good for engraving and 3D finishing
• Sintered diamond tapered ball nose — better choice when you need longer tool life and deeper 3D carving.

A supplier in Ahmedabad lists blue vacuum-brazed ball-nose diamond bits in 6, 8 and 10 mm sizes, with approximately 90 mm overall length and 20–22 mm cutting length.

If you tell me your shank size (6/8/12 mm), ball diameter, stone (marble/granite/sandstone), and CNC spindle RPM, I can recommend the exact bit size + RPM + feed rate + step-over.