All the lines are busy at the moment, please try again in a moment. +82 2 22000823. Email. COGO TOOL CO.,LTD. Verified company. Seoul - South Korea. High Performance Carbide End Mills, CBN End Mills for Steel Use Stainless (SUS), CBN End Mills for Cutting Copper, Carbide Cutting Tools Manufacturer in Korea, High Speed End Mills Series, Hard End