Product Name: 60 Degree Double Head Carbide Center DrillsModel Number: CD60-450/550 Product Parameters:1. Brand name: ... carbide5. Grain Size: Micro grain 0.6μ6. Type: Carbide center drills, Double head drills7. Flute: 2 Flute8. Helix angle: 35°9 ... , very high cost-performance. Special for center drilling on different metals, tip angle 30 degree, double head, also it can reduce the ...