Gear teeth circular pitch

The size and proportion of gear teeth are designated by a specific type of pitch. In gearing terms, there are two types of pitch circular and diametric. 

Circular Circular pitch is the distance from a point on one tooth to the corresponding point on the next tooth measured along the pitch circle as shown in Figure 57.32. Its value is equal to the circumference of the pitch circle divided by the number of teeth in the gear. While most common-size gears are based on diametric pitch, large-diameter gears are frequently made to circular pitch dimensions. 

Example 1 What is the circular pitch of a gear with 48 teeth and a pitch diameter of 6 inches ... 

Example 2 What is the pitch diameter of a 0.500-inch circular-pitch gear with 128 teeth ... 

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