These pegs are made for skatepark and very light street such as hand rails and stalls on ledges. Grinding on rough ledges will wear these pegs out very fast so if you like to grind cement ledges these pegs may not be for you. Note these pegs do not grind as fast as heatreated steel pegs but they are faster than titanium.
These aluminium pegs grind faster than titanium on steel. Just to clear any confusion, aluminium is not inherently a high friction material. Everyone has had there experience of aluminium railing being very slow, but aluminium railing is made of a very soft corrosion resistant grade. Like all metals, the higher quality grades are harder and have a lower friction coefficient. Skateboard trucks have always been made of aluminium.