Maximum Element Size
Click Refine Model and then click the arrow next to Control. Click Maximum Element Size. The Maximum Element Size Control dialog box opens. Use the items on this dialog box to control the size of the elements created by the mesh generator.
Specify the following information on the Maximum Element Size Control dialog box:
Name—Specify a name for the AutoGEM control or use the default name.
References—Specify the reference type and select the appropriate geometry. If you have selected valid geometric references before opening the AutoGEM Control dialog box, the References collector displays your selections when the dialog box opens. Otherwise, select one of the following:
Components
Volumes
Surfaces—individual, boundary or intent surfaces.
Edges/Curves—single edges or curves or intent chains and intent curves.
Points—individual points, point features, patterns of points or intent points.
Element Size—Specify the element size. Select units of length for the element size from the adjacent drop-down list or accept the default units.
* 
The value that you specify for element size serves as a target that AutoGEM tries to reach. It acts as a guideline for element creation but may not be reached exactly.
If you enter an unusually small value for the maximum element size, the software might create an extremely large number of elements. The mesh generator compares the specified size of the element with the volume of the meshed part. If the specified element size is very small, the software displays a message. If it cannot generate a mesh with elements that small, the software overrides the value specified in the mesh control with the smallest value it considers acceptable and displays a warning.