From FreeCAD Documentation
- Press the Toggle snap button to toggle snapping.
- optionally click on the down arrow to the right of the button to open the menu. The settings in this menu can only be changed if snapping is switched on:
- If the Snap to grid checkbox is checked, the cursor will snap to grid lines and grid intersections. Snapping occurs if the distance of the cursor to a grid line is 20% of the grid spacing or less. Snapping also works if the grid is invisible.
- If the Snap to objects checkbox is checked, the cursor will snap to edges of geometry and midpoints of lines and arcs.
- Snap angle specifies the angle for angular snap. Snapping will occur at multiples of this value starting from the direction of the positive X axis of the sketch. The Ctrl key must be held down for this snap. Angular snap only works when creating certain geometry.