According to AISI E-1 guidelines , chairs are essential when anchor bolts are required at the supports of a shell. Their primary functions include:

To ensure the chair is safe, engineers must verify three primary stress areas: Top Plate Stress (

To understand why AISI-compliant chairs are better, one must first understand what a non-compliant chair typically is: a few pieces of rebar tack-welded to a bent plate. In contrast, AISI E 1 Volume II Part VII requires:

These must be thick enough to prevent buckling and overstressing. Minimum thickness: At least 0.5 inches or , whichever is greater. Welding Requirements: