Columns are available a variety of configurations, most common are:

Type OO - Round shell over round pipe
Type SS - Square shell over square tube                                                                         Type SO - Square shell over round pipe
Type RR - Rectangle shell over rectangle tube
Type SH - Square shell over wide flange shapes
Type OH - Round shell over wide flange shapes

Type OO	Type SS	Type SO	Type RR	Type SH	Type OH
Other Configurations are available - call for more information