Vertical Sections

Hole locations for the vertical members should be as shown in examples A and B.

Each vertical member should have two holes at each end, 180° apart in line with the horizontal members. The size of the holes preferably should be equal, and the combined area of the two holes at either end of the verticals should be at least 30% of the cross-sectional area.

End-plates Horizontal

1. The most desirable fabrication is completely open.
2. From the illustration, if H + W = 24" (61 cm) or larger, the area of the hole, plus clips, should equal 25% of the area of the tube (H x W).
   • If H + W = less than 24" (61 cm) but more than 16 (41 cm), the area of the hole, plus clips, should equal 30% of the area of the tube.
   • If H + W = less than 16" (41 cm) but more than 8 (20 cm), the area of the hole, plus clips, should equal 40% of the area of the tube.
   • If H + W = less than 8" (20 cm), leave it open.