3mm groove in inox steel

[Roadracer_Al]

If you rearrange your clamping screw, you can do it quite straight forward with a slitting saw.  And, there's no reason the slit must be radial to the fork tube, either.  It will clamp just as well if the slit is at a convenient angle for using the slitting saw!!  The pinch bolt, however, should be tangent.



Also, the slit doesn't have to be open, or narrow.  A .25" / 6 mm wide slot will work perfectly fine.