I've tried OScarbid tools before, but the quality sucks. I ordered 5 extra bits and the first 3 fell out within minutes when milling on the part at very low feed and 70rpm on a lathe with full coolant. The carbides just explode. The first didn't even cut, it squeaked like a cat in a cauldron. The insert failed completely and tore the tool holder. The next two simply split in half, down the middle as shown in the pictures. I completed, sharpened and centered the parting with HSS China Parting 5/8. It cut through the stainless steel like butter, forming ribbon chips. I worked for many years, but Chinese high-speed steel blades cut better than carbide and do not explode. The final exploding carbide tip flew past my head and literally got stuck in a wooden cabinet 12 feet behind me. I will no longer buy OS carbide tools. waste of money and time.