STRAUB Metal-Grip Pull out resistant STRAUB Metal-Grip couplings join plain end pipes with axial restraint. STRAUB Metal-Grip provide pull out resistance in excess of the coupling’s rated working pressure. Whether for pressure or suction lines, thick or thin wall pipe, the STRAUB Metal-Grip couplings are installed quickly, safely and economically. Due to the unique design of the anchor ring, as internal pressure increases, the anchoring effect is progressively increased. The engagement of the teeth into the pipe's outside