Patent ID: 8052344

Claim:
A fastening assembly for a device comprising: a first component made of a biodegradable plastic material; a second component made of metal securely joined to the first component; a fastener for fastening the first component and the second component; a fastening surface, formed on the first component, for fastening the first component and the second component; a fastened surface, formed on the second component, fastened to the fastening surface formed on the first component; a passing hole, formed on the first component, through which the fastener passes so as to fasten the fastening surface of the first component and the fastened surface of the second component; and first and second grooves, provided on the fastening surface of the first component, which extend to an outer edge of the fastening surface of the first component and do not contact the fastened surface of the second component for guiding a degradation liquid for degrading the biodegradable plastic from outside to the a fastening surface between the first and second components while the fastened surface of the second component is fastened to the fastening surface of the first component by the fastener, wherein the first groove, being of straight line shape, reaches directly to the passing hole while the fastened surface of the second component is fastened to the fastening surface of the first component by the fastener, and wherein the second groove, being of straight line shape, is formed side by side with the first groove so as not to reach the passing hole.