In this article, we explore the main types of clamp-style rigid couplings – one-piece, two-piece, and three-piece designs – along with specialized variants like step bore couplings and double wide shaft collars (used as compact couplings). We compare their characteristics (torsional rigidity, strength, backlash, etc.) in a side-by-side table, and provide design insights and installation tips. Finally, we outline how to select and order high-quality rigid couplings from PIB Sales, an authorized Ruland distributor.