Sam i have tryed your formula and work perfect for demagnetize .... now my graver has been transmuted in 24K gold !!!
I think Sam has his equations muddled... that's the recipe for Onion soup!
Try not to be too upset mrthe. I'm sure Sam meant no harm. There are a few small errors in the formula, I'm sure Sam will have it worked out soon. In the mean time try to look on the bright side having a sharp graver isn't everything you know.
I have Jeroen's one now, he showed it and gave it to me as a present. Yes I could afford one, but always a pleasure making a tool by yourself and doing some recycling on garbage.
I'm with Arnaud,i have the MacGyver syndrome,i like make my own tools is funny and ever you can learn something new.