Surgical scalpels consist of two parts, a blade and a handle. The handles are often reusable, with the blades being replaceable. In medical applications, each blade is only used once (sometimes just for a single, small cut).

The handle is also known as a "B.P. handle", named after Charles Russell Bard and Morgan Parker, founders of the Bard-Parker Company. Morgan Parker patented the 2-piece scalpel design in 1915 and Bard-Parker developed a method of cold sterilization that would not dull the blades, as did the heat-based method that was previously used.

The handle of medical scalpels come in several basic types. The first is a flat handle used in the #3 and #4 handles. The #7 handle is more like a long writing pen, rounded at the front and flat at the back. A #4 handle is larger than a #3. #5 handles are also common, and are round, with a patterning to ensure a non-slip grip. Blades are manufactured with a corresponding fitment size so that they fit on only one size handle. The following table of blades is incomplete and some blades listed may work with handles not specified here.