Sketch Tab Reference (Document Settings)
Sets the default snap spacing, grid settings, and other sketch settings for the active Inventor file.
Access
Ribbon: Tools tab 
Options panel Document Settings 
. In the dialog box, click the Sketch tab.
The active document type determines the available options.
Snap Spacing
Sets the spacing between snap points to help with precision when sketching in the active part or drawing. The settings for the two axes can be different.
X
Sets the snap distance for the X axis.
Y
Sets the snap distance for the Y axis.
Grid Display
The sketch grid aligns according to the sketch coordinate system.
Snaps Per Minor
Sets the distance between minor grid lines relative to the specified snap distance. For example, if you set the X snap distance at 0.0625, and specify two snaps per minor, the minor lines are spaced 0.125 apart.
Major Every Minor Lines
Sets the number of minor lines to appear between major lines. Major lines appear heavier in the grid display.
Options panel Application Options and on the Sketch tab, change the settings.Line Weight Display Options
Display Line Weights
Controls the display of line weights in model sketches. Clear the check box to show lines without weight differences. This setting does not affect line weights in printed model sketches. To set the actual line weights in print, use the Sketch Properties toolbar.
- Display True Line Weights When selected, shows line weights as they would appear on paper. For example, regardless of zoom magnification, a line 0.5 inch thick is the same as the height of 0.5-inch text.
- Display Line Weights by Range (millimeter) When selected, shows line weights according to values you enter. Values range from smallest (left) to largest (right).
3D Sketch
Auto-Bend Radius
Sets the default radius for corner bends automatically placed on 3D lines as you sketch them.
Options panel Application Options and on the Sketch tab, change the setting.