Patent ID: 8192157

Claim:
A fan frame structure comprising: a plastic casing including an air inlet in a top side thereof and an air outlet in a bottom side thereof, with the plastic casing further including an accommodation space in communication with the air inlet and the air outlet, with the bottom side of the plastic casing further including a plurality of corners each having a first fixing portion; and a metal fixing frame including a base having a shaft tube seat in a center thereof, with the base further including a plurality of support arms extending outward from an outer periphery thereof, with each of the plurality of support arms having a first end interconnected to the base and a second end forming an assembling hole and a second fixing portion engaged with one of the first fixing portions of the plastic casing, wherein the assembling hole forms two annular openings on two end faces of the second end respectively, with one of the second fixing portions of the metal fixing frame including a plurality of trenches formed on at least one of the two end faces and circumferentially surrounding at least one of the two annular openings of the assembling hole, with each of the first fixing portions of the plastic casing enveloping the two end faces of one of the second fixing portions of the metal fixing frame by injection molding.