HDU vs HDU-E Hold Downs Explained (Technical Topics) | Royal

In this solo episode of Build Better Homes, Royal Mortier introduces a new recurring segment called Technical Topics, focused on engineering-related changes that directly affect residential construction. This first Technical Topics episode breaks down a major hardware shift many builders and designers are already encountering in the field: Simpson’s transition from the HDU hold-down series to the new HDU-E series, along with the introduction of SABR (Saber) anchor bolts. Royal walks through how and why the HDU-E series delivers higher tensile capacity with fewer screws and thinner gauge steel, what has changed in screw orientation, and how these updates affect real-world design decisions, pricing, and installation tolerance. He also explains where retrofit options disappear at higher capacities, and why anchor bolt placement accuracy becomes critical as loads increase. The episode closes with a practical design tip that has dramatically reduced misplaced anchor bolts across thousands of homes: dimensioning hold-down anchor locations directly on foundation plans. This is a highly technical, field-driven episode aimed at engineers, designers, framers, and builders who want fewer surprises during construction and inspections.Topics CoveredWhy the HDU series is being phased outKey differences between HDU and HDU-E hold downsHorizontal vs angled SDS screw installationHow geometry increases tensile capacityCapacity comparisons (HDU2 → HDU-E3, HDU4 → HDU-E5, HDU5 → HDU-E7, HDU8 → HDU-E9, HDU11 → HDU-E13, HDU14 → HDU-E17)Gauge changes and reduced screw countsRetrofit limitations at higher hold-down capacitiesSB vs SABR anchor bolts (Grade 36 vs Grade 55 steel)Why SABR bolts simplify design and sourcingPricing differences and where savings still existA proven method to reduce anchor bolt retrofits by over 90%Key TakeawayHardware keeps evolving. The builders who stay ahead are the ones who understand why it changed, not just what changed.