carborundum disc
carborundum disk

The best time to see these works is late afternoon on a clear day when the sun electrifies the drawing on their stainless steel surfaces, which Smith achieved by grinding with an electrically powered carborundum disc.

Large samples (above the size of two clenched fists) must first be trimmed on a saw with a large radius blade (steel impregnated with diamond or a compressed carborundum disc), lubricated with water.