Abstract: An apparatus for continuously mixing liquid resin and powdered hardeners in accurate proportions to produce adhesives is described. A mixing screw and tube lock into a mounting from which they may easily be removed for quick cleanout. The preferred screw has mixing threads that are of the buttress type, having rectangular leading and sloped trailing edges in cross section. The screw is divided into transporting and high shear rate mixing sections. In the transporting section, the rectangular thread edges face in the direction of material flow through the tube. The high shear rate section's buttress threads are modified by spiral cuts in the threads, at a greater lead than the buttress threads. This section is installed with the sloped edge facing the direction of material flow.