... following size holes 3mm,4,5,6,8,10,12,14,15,16,18,20,22,23,25,28 ... bits do not have a pilot drill, they are best used in a drill press or with a guide to start ... or clamped to the job.Until it starts to drill then I remove the piece of wood and ... continue drilling.I use a coreless drill at a low speed with a spray bottle ... 8kgs/setsizes in case:4mm,5,6,8,10,12,15,20,22,25,28,30,32,35, 38 ...