Ladder with box rails having a collar

A ladder comprising:

• a first box rail having an outer web with an outer opening and an inner web with an inner opening, the inner opening in alignment with the outer opening, the inner opening having a circumference which is smaller than a circumference of the outer opening;
• a second box rail in parallel and spaced relation with the first box rail;
• a hollow collar disposed in between the inner opening of the inner web and the outer opening of the outer web, the collar having a stem having a plurality of segments, the segments separated by slots, each segment having a top and a bottom;
• and
• a first rung attached to the first box rail and the second box rail, the first rung having a first end that extends through the outer opening, the collar and the inner opening, the collar has a hollow base with a cross-sectional shape which conforms with a cross-sectional shape of the first rung, the first rung extending through the base and the stem:
• wherein the bottom of the segments are directly attached to the base and wherein the tops of the segments define an outer stem circumference which is larger than an outer circumference of the base, an inner stem circumference has a cross-sectional shape which conforms with the cross-sectional shape of the first rung in an installed configuration, the outer circumference of the base is larger than the outer circumference of the inner opening in the inner web.