Figure 53.

Paragraph 68. The open mortise and tenon joint is used in the construction of rectangular frame work which employs heavy timbers. This joint, however, is not in very common use. It is very similar to the end half-lap joint, but is a little more complicated.

In laying out the open mortise and tenon joint the tenon piece A will be laid out and cut in the same manner as in cutting the tenon for the blind mortise and tenon joint. The mortise piece B is laid out with a mortising gauge in the same manner as any other mortise except that, since it is at the end of the material, instead of being bored and chiseled out it can be ripped down with the rip saw and cut out with a chisel.