The clover insert is our maximum threshing insert, and it is used in extremely hard thresh conditions. Used in crops like grass seeds, flax, durum and hard-to-thresh wheat varieties. This insert is typically installed into the front concaves in limited numbers or ordered as a full concave. These inserts are individually replaceable, 180-degree reversible and boronized to extend the life of the insert. Boronizing is a thermo-chemical hardening process used to improve the life and performance of metal components to strengthen resistance to corrosion and abrasive wear. Right hand configuration.