Comment by imtringued

I didn't use it for exams, but I once went to a regional clothing store known for being extremely cheap and poor quality and I bought a 1€ mechanical pencil there. Surprisingly, that mechanical pencil had an amazingly well engineered metal collet instead of the usual plastic ones. I've used that pencil for years and my only complaint is that if you don't tighten it enough, it'll unscrew itself and snap your lead.