BT40 End Mill Holders With Coolant Channels 25,000RPM G2.5, BT30 End Mill Holders 20,000 RPM G2.5, BT40 End Mill Holders 15,000 - 25,000 RPM G2.5/G6.3 & BT50 End Mill Holders 15,000 - 25,000 RPM G2.5/G6.3