Parametric hex bits, I've added as many controls over parameters as I could think of, if there is anything you would like added please let me know.

When adding the magnet slot, set the diameter and height of your magnet. Simply set a pause at height during slicing. There is a .4 mm gap about the magnet height.

Bit Styles: Hex Double Hex Hex Socket Square Square Socket Double Square Star

Update: Fixed an issue with measurements not being used accurately. All sizes should be rendered correctly.