Jim Kingshott explains how-to drawbore a mortice and tenon

3-Second Blueprint (English)

1. Bore the mortise from both sides once the lead screw pricks through, then spin the bit backwards to mark the assembled tenon.
2. Offset the tenon hole slightly toward the shoulder and reference face so driving a tapered pin pulls the joint tight without clamps.
3. Split riven wooden treenails along the full grain and size them in a dowel plate to avoid weak short-grain commercial dowels.