The ITSN-433 Shim Seat is a precision replacement shim seat designed for indexable turning toolholders that use TNMG-style triangular carbide inserts. Manufactured from hardened, wear-resistant material, it provides a stable seating surface that ensures accurate insert positioning, improves machining consistency, and protects the toolholder pocket from premature wear. The ITSN-433 is designed for 1/2" inscribed circle (I.C.) inserts, with a 3/16" thickness and 3/64" corner radius, making it ideal for negative-rake turning applications in production and general machining. Compatible with a wide range of external turning toolholders, it is a dependable replacement part for maintaining precision and extending toolholder service life.