A local coordinate system is associated with each member. Each axis of the local orthogonal coordinate system is also based on the right hand rule.

The following figures show a beam member with start joint 'i' and end joint 'j'. The positive direction of the local x-axis is determined by joining 'i' to 'j' and projecting it in the same direction. The right hand rule may be applied to obtain the positive directions of the local y and z axes. The local y and z-axes coincide with the axes of the two principal moments of inertia. Note that the local coordinate system is always rectangular.

When Global-Y is Vertical

When Global-Z is Vertical (that is, SET Z UP is specified)

A wide range of cross-sectional shapes may be specified for analysis. These include rolled steel shapes, user-specified prismatic shapes etc.. The following table shows local axis system(s) for these shapes.

Wide Flange - ST	Wide Flange - TB	Wide Flange - CM
Angle - ST	Angle - RA	Angle - LD (Long legs back-to-back)
Angle - SD (Short legs back-to-back)	Wide Flange - T	Channel - ST
Channel - D	Prismatic	Tube - ST

Local axis system for various cross sections when global Y axis is vertical

Labels for the local axes of a single angle as defined in AISC publications.

Wide Flange - ST	Wide Flange - TB	Wide Flange - CM
Angle - LD	Angle - SD	Channel - ST
Wide Flange - T	Channel - D	Prismatic
Tube - ST	Angle - ST	Angle - RA

Local axis system for various cross sections when global Z axis is vertical (SET Z UP is specified).