Abstract
From the machining elements of a thickened tooth, this paper is introduced that what the OFFSET DESIGN is and what the aim of the OFFSET DESIGN is. Further more, the paper brings forward the prerequisite checking for validating the legitimacy of the offset value. This study also shows advantages and disadvantages of the OFFSET DESIGN. Based on the direct proportion character of the tooth's rigidity along a thicken-tooths width with a thickened tooths thickness (on the reference circle), the bending strength calculation at a thickened tooths root is solved in this paper.