We’ve been receiving a lot of requests lately from engineers wanting to know exactly what the difference is between Simpson Strong-Tie’s relatively new adhesive, SET-3G™, and its predecessor, SET-XP®. Both are epoxy-based adhesives used to anchor threaded rods and reinforcing bars in concrete base material for structural applications. If you perform a live pull test on a ½” diameter mild steel rod embedded 4″ deep in 3,000 psi uncracked normal weight concrete, the result will likely be the same; in both cases, the steel rod will break in a ductile manner at around 11 kips. You can see this hourglass shaped steel failure mode happening in Figure 1. (To learn more about anchorage failure modes and ductility, check out this blog). Yet, the SET 3G design values shown in ESR-4057 come out ahead. But why?