A method of manufacturing a section is formed from a blank having the perimeter of a truncated generally isosceles triangle. Each angled side of the truncated generally isosceles triangle includes a plurality of substantially semi-circular channels. The long axis of each substantially semi-circular channel is substantially parallel to the base of the truncated generally isosceles triangle. The top of the substantially semi-circular channel intersects the front surface of the section knife. The bottom of the substantially semi-circular channel intersects the back surface of the section knife. A cutting edge is formed at the intersection of the substantially semi-circular channel and the back surface of the section knife.