What radius should I use for square and rectangular tubes?

For steel and stainless steel, you should draw the corners of square and rectangular tubes as follows:

• Outer radius = 2x wall thickness (The value ‘2’ is an average value of the size of the radii specified in the relevant standardizations).

• Inner radius = 1x wall thickness.

The following applies to aluminum:

• Outer radius = maximum 0.6 mm

• Inner radius = 0 mm (right angle)