Good at first. Chuck is fine. The plastic body is ok. You have done your job. will I hold on to them? Probably not. These drills are really poorly made. They are *very* coarse and when I got them they were caked in the milling medium. Many of the bits were noticeably uneven when unpacked. Also, they're not sorted, so you'll have to use a fairly subtle measuring tool and iterate over the heap to figure out which bit is which. Sorting/measuring to find the bit I need, I realized that bit tolerances are everywhere. It should go from 0.3mm to 3.0mm in 0.1mm increments, but the drills themselves are +-0.025mm. In short, these drills are a sloppy mess. but they worked in a pinch. Wouldn't order again. and can throw them away!