PLUSNUT MULTI GRIP NUT STEEL METRIC RIVET NUT THREADED INSERT M5 M6 M8

M8 X 1.25 pitch - 0.5 - 7.1mm grip range, hole size 11.1 - 11.5. M6 X 1mm pitch - 0.5 - 7.1mm grip range, hole size 8.8 - 8.93. M5 X 0.8 Pitch - 0.5 - 4.5mm grip range, hole size 7.48 - 7.62. For use with materials of multiple or variable thicknesses.

eBay