using the a1085 database from the steel tube institute in risa-3d

Using the A1085 Database from the Steel Tube Institute in RISA-3D

RISA-3D features the A1085 HSS sections from the Steel Tube Institute. The Steel Tube Institute provides the values for A1085 HSS sections' geometric properties used in RISA-3D. A1085 has very important use applications in the HSS or steel tube industry. Why? 

  • A1085 provides an allowable 50 ksi minimum yield stress for all HSS shapes.

  • Because the tolerance is tighter on A1085 HSS shapes, A1085 allows the use of full nominal weld thickness in strength calculations. This gives A1085 HSS shapes greater strength unlike other steel materials which have to use reduction factors such as 0.93. 

The A1085 material has already been added to the RISA-3D's default materials spreadsheet. The Ry=1.25 and Rt=1.15 default spreadsheet values are also per the Steel Tube Institute.


To select the shape from the database, open the Shape Selection window either from the Section Sets spreadsheet or the member Properties section. You can select the AISC or AISC_historic database. Scrolling all the way down to the bottom of the Shape Name box, the shape names change to have _A1085 appending to the end of the names.


For information on HSS connections, check out our video here.