Grade overview Solid carbide threading tools Coated cemented carbide PVD Grade Grade description A Turning KTG402 PVD coated P20–P30/M20–M30 carbide substrate for steel and stainless steel. Especially for thread forming tools. KTG4015 PVD coated P20–P30/K20–K30 carbide substrate for steel and cast iron. Especially for thread forming tools. B Milling Uncoated cemented carbide Grade Grade description YK40F Uncoated K20–K30/N20–N30 carbide substrate for cast iron and non ferrous materials. C Drilling D Information Technical E Index C 143