It gets slick from the heat of friction. I always use bee's wax when I'm running Finnish sscrews into a hard wood like oak. In cabinets and skirt boards risers and treads. Bars of soap is another good option. I like dove or Irish spring. Lol. And they make a huge difference. From breaking screws to not braking any. With predrilling. Sent from my LGAS995 using Tapatalk