# System data

> [HTML Version](system_data.html)

At this section, common general data and settings for the whole gear system can be defined, such as:

- Normal module

- Normal pressure angle

- Helix angle

- Basic rack addendum: haP is the coefficient to define the addendum of the standard basic rack tooth profile defined as addendum = haP \* mn. This value is normally equal to 1, thus being the addendum = mn.

- Required clearance: The required clearance is a restriction that sets a minimum permissible distance between the tooth tips of unconnected gears to prevent them from colliding with each other.