I am considering buying a set of Mohs hardness scratch pens (aka hardness picks). As a hobbyist the price is quite high, starting at 300 USD and upwards for a complete set. I can accept this price if I can expect them to do their job for a lifetime, or at least for a decade.
I assume that the tip of these picks are machined to have a sharp edge, probably a single point.
All cutting tools, like drill bits or saw tooths loose this sharp edge with use, so I assume the same will happen with these scratch pens. But when googling for this, I havent found a single source that talks about how to maintain/sharpen these pens, and I haven't found a single source that talks about how long they last or if they will need replacing.
So let me try and put this into a few questions:
- How long can I expect such a pen to last and how long will it do its job well?
- Do people sharpen or otherwise maintain their scratch pens?
- Do people replace their scratch pens?