The Smith & Wesson SW series, most commonly referred to as the Smith & Wesson Sigma, was Smith & Wesson's first venture into using synthetic materials in pistol construction, with high-strength polymer material for the frame.

The Smith & Wesson SD Series is a polymer-framed, striker-fired semi-automatic pistol line that the American company Smith & Wesson introduced in 2010, replacing the SW / Sigma line. Smith & Wesson started manufacturing "SD VE" models in 2012. The SD VE models have stainless steel slides. Aside from slide color differences, SD and SD VE pistols are mechanically identical.