... Hardness, Abrasion Resistant, Corrosion Resistant. Precision Process. PCB Drill Roote Material: Tungsten steel.Type:RE Diameter (d) Blade(l) ... ; Fax : 0769-8778-6557 Add: No.6 Xianda Road, Longteng Industrial Zone,Guancang Village, Zhangmutou Town, Dongguan City, Guangdong Province, China