Undercut saw

A saw for undercutting door jambs or trim comprising:

• a general purpose saw blade attached to a general purpose saw;
• an undercutting saw blade attached to a flange, the flange having a first portion attached to the undercutting saw blade, a second, offset portion that extends substantially orthogonally away from the first portion and a third portion that extends substantially orthogonally away from the second portion in a direction substantially opposite that of the first portion and in a plane generally parallel with the first portion, the third portion of the flange having a saw attachment portion comprising an internal blade pocket structured to removably receive a portion of the general purpose saw blade chucked into the general purpose saw, and fasteners which are used to attach the flange to the general purpose saw blade disposed within the internal blade pocket by a clamping action against a surface of the general purpose saw blade and not extending through bores or apertures in the general purpose saw blade such that when the flange is to be removed from the general purpose saw blade the fasteners are loosened and not removed entirely, the fasteners further being threaded through a wall of the flange and threadingly extending into internal blade pocket to accomplish the clamping action.