Pitzl connectors are sliding-dovetail structural connectors made in Germany. I was introduced to them when a recent project called for an open-riser stair made of 3×12 white-pine timbers with concealed fasteners. The aircraft-grade aluminum connectors come in a range of sizes from 1 in. by 2 in. to 5 in. by 25 in. We sourced ours from a canadian supplier (herrmannframes.com) that also helped us size them, ensuring they could handle the loads imposed.

The install is simple and straightforward. The connectors separate into two halves and are locked together with two hex screws. The HVP versions also include a locking bar in addition to the two screws to resist uplift. Once the two Pitzl shapes are transferred to the two timbers, the mortise is cut with a small router. I made the mortises about 1⁄64 in. deeper than the thickness of the Pitzl body so the joint would tighten as the connectors are seated. After lining up the connector halves in their pockets, a self-centering bit drills the holes for the included structural screws.

When it comes time to assemble the timber joint, the two halves of the joint are aligned, then a couple mallet blows ensure the connection is tight before the retaining screws are installed. I really like these connectors and I’m already seeing places where they can make our lives easier in the future. Prices start around $13 each.

Ben Bogie, lead carpenter with Kolbert Building in Portland, Maine

Photos: courtesy of Nathan Rinne, courtesy of Ben Bogie 

From Fine Homebuilding #282