The present disclosure is drawn to covers for electronic devices. In one example, a cover for an electronic device can include an aluminum or aluminum alloy cover frame having an opening. A magnesium or magnesium alloy cover panel supported by the aluminum or aluminum alloy cover frame within or over the opening. A protective coating can be over a surface of the aluminum or aluminum alloy cover frame and a surface of the magnesium or magnesium alloy cover panel. A chamfered edge can include a chamfer at an edge of the aluminum or aluminum alloy cover frame. The chamfer can expose the aluminum or aluminum alloy cover frame beneath the protective coating, and the chamfer at the same time does not expose the magnesium or magnesium alloy cover panel.