Seco 396.18/19/20 thread mills are versatile, cost effective process tools for anyone facing a variety of threads, parts and workpiece materials on the same machine. Multi-tooth indexable insert cutters use a double sided multi-tooth insert usable above 14 mm for both internal and external threads. The mills have up to 9 inserts for faster production time. A 40 mm insert is available with different thread profiles and pitches. Precision ground for perfect thread forms, it is available in our tough and durable F30M grade.