I needed to drill a really tiny hole in a mini-blind rod. That would allow me to pass a pin through the rod to attach the plastic eye thinga ma jingy.The drill bit size was smaller than the thickness of a paper clip. I spun it clockwise and it drilled out the hole pretty quick. Anyways this pen drill was easy to use. easy to set up and break back down. The pen drill quality is good but man you gotta take a look at how tiny a drill bit they include in this set. IT IS SO TINY!And I don't know what Sheerness is to give it a rating.