NEMA 210 frame three-phase general purpose AC motors have a standard 1-3/8" diameter, 3-3/8" length shaft whose center is 5-1/4" above the mounting surface. Variations to the frame's standard dimensions and design are indicated by a letter designation following the frame number, such as 213TCV. The letter “T” specifies integral HP motor dimension standards set by NEMA in 1953 and 1964, “C” indicates that the motor can be face mounted, and “V” indicates that the motor can be vertically mounted. These frame standards and letter designations are defined by the National Electrical Manufacturers Association (NEMA).