Step stool

[0001]FIG. 1 is a front, right, and top perspective view of a step stool, showing my new design;

[0002]FIG. 2 is a rear, left, and bottom perspective view thereof;

[0003]FIG. 3 is a front elevation view thereof;

[0004]FIG. 4 is a rear elevation view thereof;

[0005]FIG. 5 is a left side elevation view thereof;

[0006]FIG. 6 is a right side elevation view thereof;

[0007]FIG. 7 is a top plan view thereof;

[0008]FIG. 8 is a bottom plan view thereof;

[0009]FIG. 9 is an enlarged view of an encircled area labeled “9” in FIG. 1;

[0010]FIG. 10 is an enlarged view of an encircled area labeled “10” in FIG. 1;

[0011]FIG. 11 is an enlarged view of an encircled area labeled “11” in FIG. 2; and,

[0012]FIG. 12 is an exploded, front, right, and top perspective view thereof.

[0013]The evenly-dashed broken lines depict portions of the step stool that form no part of the claimed design. The dot-dashed broken lines, as shown in FIGS. 1, 2, 9, 10, and 11, depict the boundary of the enlargements that form no part of the claimed design.