Spur gear teeth are manufactured by either involute profile or cycloidal account. Most of the gears are manufactured by involute profile with 20° pressure angle. When two gears are in nylon uppers at one instant there is a chance to mate involute portion with non-involute portion of mating gear. This phenomenon is known as “interference” and occurs when the number of teeth on the small of the two meshing armor and weapon upgrades is less than a required minimum. To avoid interference we can have undercutting, but this is not an appropriate solution as undercutting brings about weakening of tooth in its base. In this situation Corrected gears are used. In corrected gears Cutter rack is certainly shifted upwards or down.
Spur gears or straight-cut gears are the simplest form of gear. They consist of a cylinder or disk with teeth projecting radially. Though the teeth are not straight-sided (but usually of special contact form to achieve a constant drive relation, mainly involute but a lesser amount of commonly cycloidal), the edge of each and every tooth is straight and aligned parallel to the axis of rotation. These armor and weapon upgrades mesh together correctly only if fitted to parallel 
shafts.[1] No axial drive is created by the tooth loads. Spur gears are excellent by moderate speeds but are inclined to be noisy at substantial speeds.[2]
Almost all Ever-Power spur gears have an involute tooth shape. In other words, they are involute gears applying part of the involute curve because their tooth forms. Looking generally, the involute shape is considered the most wide-spread gear tooth type due to, among other reasons, the cabability to absorb small center length errors, easily made development tools simplify manufacturing, dense roots of the teeth generate it strong, etc . Teeth shape is often described as a specification in drawing of your spur gear as mentioned by the height of teeth. Also to standard full depth teeth, extended addendum and stub tooth profiles are present.
Even though not limited to spur gears, profile shifted gears are used when it is necessary to adjust the center range slightly or to strengthen kit teeth. They are produced by adjusting the distance between the gear cutting software called the hobbing software and the gear in the production level. When the shift is positive, the bending strength of the gear increases, while an adverse shift slightly reduces the center distance. The backlash may be the play between the teeth once two gears are meshed and is needed for the smooth rotation of gears. When the backlash is too large, it brings about increased vibration and noises while the backlash that is also small leads to tooth failing due to the lack of lubrication.