We offer convex and concave form relieved milling cutters. Excellent quality delivered to your door anywhere in the world. Convex cutters hss solid cutters for milling concave forms on components. Convex cutters used for milling concave half circles. Concave cutters are machine form relieved - the profile remains constant throughout cutter life, provided that on re-shapening, the face of the tooth is ground radial-to-centre.