These spikes are ideal for staking in aluminum garden or paver edging. Can be useful in other applications as well; ie.: nailing 6″ X 6″ ‘s together for retaining walls, provide strong hook to hang garden tools on, etc. The diameter of these spikes is 3/8″ and they provide for a good snug fit in garden edging. These spikes are steel, spiral and non-galvanized, when they rust they hold on to the ground better.