4 Flute Spiral Chamfer Cutter 30 60 90 120 Degree Unequal Spiral Angle Anti-Vibration Smooth Surface Deburring Tool for Stainless Steel. 90 Degree 4 Flute Chamfer Drill Bit, Solid Carbide Spiral V Groove Deburring Tool for Steel /Stainless steel. (2) Material:Carbide Tungsten. (3) Coating: AlTiN Coating. (4) Valve stem diameter: 4mm, 5mm, 6mm, 8mm, 10mm, 12mm. (5) Best applicable materials. AiTiN:garbon steel/salloy steels/tool steels/alloy steels/pre-hardenedsteel.