A heavy fraction oil is catalytically cracked by contacting the oil with a catalyst mixture consisting of 60 to 95 wt % of a base cracking catalyst containing an ultra stable Y-type zeolite and less than 0. The fuel injector tube further includes a fuel passage extending from the inlet end to the outlet end along a longitudinal axis of the polygonal tube, a plurality of air passages extending from the inlet end to the outlet end and surrounding the fuel passage, and a plurality of fuel holes. The cantilever has a magnetic material and a longitudinal axis. A photoresist layer is formed upon the exposed conductive layer.