The shank is the band portion of a ring that encircles your finger. It connects to the head (where the center stone sits) and provides the structural foundation of the ring. Over years of daily wear, shanks can thin out, bend, or even crack—especially at the bottom where friction is greatest. When a shank becomes too thin (under 1.5mm), jewelers typically recommend a half-shank or full-shank replacement to restore the ring's integrity and prevent breakage.