AngleLock™ Threaded Inserts — Single and Double, When Used to Prevent Sliding on the 40 × 40 Profile

This white paper determines the effect of tip engagement on the slip strength and consistency of AngleLock™ single and double self-tapping threaded inserts used as end connections on the 40 × 40 mm (40-6, M6) extruded aluminum profile. When the insert is installed at the correct height (2.8–3.1 mm), its tip plastically deforms the edge of the mating profile and forms two bearing notches. This adds material shear to a joint that otherwise holds by friction alone. Both inserts were tested in vertical shear at center span, with the tip engaged and with it not engaged. All specimens used the same profile, fixture, loading rate (5.08 mm/min) and bolt torque (20.3 N·m). Results are reported at yield (0.3 mm offset), joint slip and peak load, together with specimen-to-specimen variation. On the double insert, tip engagement raised the minimum load at joint slip by 91%, from 20.4 to 38.9 kN, and reduced the coefficient of variation from 23% to 3.8%. On the single insert, engagement raised the minimum slip load by 9%, from 17.7 to 19.3 kN. It also lowered the offset yield, which is attributed to local bearing deformation at the notches. With the tip engaged, the double insert carried about twice the slip load of the single insert. It also outperformed standard-duty and heavy-duty corner brackets by 316% and 126%. The paper also covers insert design, installation-height control with a go / no-go gage, application guidance and data reduction methods, and ends with a plain-language user guide for installers.