Rivet Nut Sizes: M3 x 0.5, M4 x 0.7, M5 x 0.8, M6 x 1, M8 x 1.25, M10 x 1.5, M12 x 1.75mm. Suitable for rivet nuts in aluminium, steel and stainless steel. We make sure to keep our prices competitive by buying in bulk and keeping the overheads low.