The beautiful and powerful knuckle-hinge joint is used to support the swing-out legs of the drop-leaf table.
Lay out a square equal to the thickness on the ends of the two equal-sized pieces.
Draw diagonals from the corners of the square to find the centers.
Inscribe a circle within the square on each end.
Saw down the diagonal line to intersect the circle to form the shoulders.
Trim the ends down to the circles with a chisel and then plane away the corners to leave cylinders on the ends of both pieces.
Use a gauge to mark the segments of the knuckles on both pieces so that they are precisely equal.
Mark alternate sections with Xs and saw down the shoulders on the waste side of the lines.
Chisel out the waste and assemble the two pieces.
Carefully drill through the centers to insert a 3/16 inch rod for the pin.
Permission of The University of North Carolina Press