- We, Kumha, are the company manufacturing all kinds of cutting tools, the materials are diamons(PCD, PCBN), carbide , HSS, And circular saw blade, router bit, 8 cutter, for woodworking and HSS knife are among our items. Kumha`s products are exported to about 20 countries. Diamond(PCD) tools for PCB(Printed circuit board) cutting, carbide circular saw for metal cutting are major products.www.kumha.co.kr