TNMG331MR-WP25CT aka 4170573 TNMG160408MR WP25CT is a 3/8″ i.c. neutral rake double sided turning insert .015″ corner radius. The WP25CT is used in Steels and stainless steels where there is a slight interruptioned cuts it is a Tin-TiCn,ALox,Tin coated insert