Aluminum Oxide Powder The Aluminum Oxide Powder is a strop abrasive with pure aluminum oxide which has no wax binders. A little goes a long way, put a pinch of the aluminum oxide powder on the strop to maintain a razor edge on your tools.This is recommend for use on strops. Aluminum oxide powder is insoluble in water , its hardness makes it suitable for using as an abrasive component with cutting tools. It does not penetrate the skin. Aluminum oxide is almost the hardest abrasive that restores surfaces or natural enamel. The abrasive particles are extremely higher on a scale of hardness and effectively reduce irregularities.