I know all cars have problems, I was using the old DSM always break joke, apparently it isn't funny...sorry
They are simply metal replacements. The stock ones can wear funny or even wear down to where pieces break off.
They are actually OEM hyundai parts from their 4b11 motor. Most people have no issues with doing this, but mine seem to be off. It's funny Hyundai used metal though, I guess they knew what they were doing haha.