"Bought these because I needed long bits to drill holes for coach bolts.
Only really needed the 10 x 400 one, but was very impressed with how easy drilling a 200mm hole with this was. I'd expected drilling 30-or-so of these to be quite hard work, but these bits drill through pressure treated softwood beams and posts in just a few seconds.
M10 coach bolts pushed through the holes cleanly and easily.
Screw points a nice touch for accurate positioning of holes."