mitered half lap picture frame

The miter joint is often used to form the corners of picture frames. This popular joint hides the end grain of the frame parts and creates a continuous grain or profile pattern around the frame corner. The downside of a miter joint is that the end grain to end grain connection is not as strong as a joint formed by connecting long grain.

You can strengthen a miter joint with a hidden half lap connection - called a mitered half-lap joint. The result gives you a conventional-looking miter joint from the front, but the back of the joint resembles a half-lap. This joint may sound complicated, but it is actually easy to make with a router table and the Rockler Router Table Half Lap Jig.

Watch: Making Half-Lap Joints with a Router Table Jig

Half-Lap Joints

Half lap joints boast maximum glue area, resulting in an incredibly strong joint. A variation of this joint is the mitered half lap. This joint gives you the appearance of a conventional-looking miter joint from the front, but the strength of a half-lap. The trick to this joint is that the tongue of one half of the joint is mitered at 45°, and it nests into a mating half-lap with a shoulder mitered at 45°.

This joint may look complicated, but it is not difficult to make when you use a router table and the Rockler Router Table Half Lap Jig.

Mitered Half Lap Joint

mitered half-lap corner joint

Download the Half Lap Picture Frame Project Plan

picture frame plan download button

Router Table Half-Lap Miter Jig

router table half lap jig

There are a number of ways to form the mating parts for a mitered half lap joint. You can use a tenoning jig and standard saw blade, a band saw or a router table and jig. The Rockler Router Table Half Lap Jig is the only jig on the market that makes it possible to easily cut both regular half lap joints (right and center insets) and mitered half lap joints (left inset) at the router table.

half-lap miter jig and router table making frame parts

The front and back tongues of the four corners of the picture frame overlap to create strong mitered half-lap joints. These half laps are formed using the Rockler Router Table Half Lap Jig . The side frame workpieces have mitered ends. A 3/8"-deep recess is removed from the back faces of these frame parts (left), creating a front-facing tongue in the mitered portions of these part ends. The top and bottom frame pieces have 3/8"-deep half lap recesses angled at 45 degrees on each end of the parts, and these recesses are removed from the front faces of the workpieces (right). The back tongue of the half lap on these parts remains square.

half-lap jig micro adjust

Steel set screws built into registration pins are fine-tuned during setup to align the Router Table Half Lap Jig to cut exactly at 90° and 45°.