Irwin has always served me well. Why package 12? This is the most common size of pre-drill screw I use, but often I need to drill through metal and this is perfect for pre-drilling, ready for the next size drill bit. They replace all the cheap bits I've gotten over the years. I rarely come across boring beats. Also sold at local hardware stores and can be easily returned to the store for replacement. Now if you break bit by bit or have trouble with them dulling on the metal when you putβ¦