The Screws were used in an experimental P Bass which I made from Oak! (being a carpenter, I get a lot of good quality off-cuts). When new, being decent quality, the screws drove into the hard wood perfectly. However, about a month later when I came to adjust the height of my pick-ups, two of the screws refused to budge and I ended up rounding the heads off. This was through no fault of the screws but was due to the high tannin content in Oak which can eat steel. As a carpenter I should have realised this earlier. I managed to remove them cleanly with pliers in the end!
In summary;
Good quality screws, perfect for use in normal tone woods, will be buying more very very soon but oiling them well before they go back in!
Oak.... Excellent tone wood, but a bit heavy and likes to eat steel! :)