25.2.1 The face of a 2-wire parallel-blade attachment plug shall be in a plane perpendicular to the major
axis of the blades (compliance shall be determined by full insertion, as described in 26.6.1, into the cord
connector described in 26.1.1) and shall be 1.000 ±0.025 by 0.750 plus 0.000 minus 0.020 inch (25.40
±0.64 by 19.05 plus 0.00 minus 0.51 mm) with the blades centered, with a maximum 7/32 inch (5.6 mm)
radius at the corners. The 1-inch (25.4 mm) dimension shall be perpendicular to the width of the blades.
See Figure 25.2.?