Smart-Bit Pre-drilling and Countersinking Tool for Fiber Cement Board such as James Hardie Fibre Cement Board by Smart-Bit by Smart-Bit

Seems expensive but for a specialty bit with carbide cutters it’s actually what you’d expect. Well made and has saved me a lot of time.

Done with 1/3rd of an 1100 sq. foot project countersinking for thousands of screws in Hardie backer (.42" thick). Comes bit bits for both thicknesses and it is still countersinking as if brand new. Countersink is deep enough for off-brand tapcons which have a larger diameter head. Glad I paid the relatively high price!

I know tools and I know once I see them that it will be crap or great. This bit worked so well. I’ve drilled 6 counter sunk holes per hardie board plank, times that by 200 plus planks, and I didn’t have to change the mason bit at all. That’s over 1200 countersunk holes. Very pleased with this purchase. Also they send spare mason bits anyway. How awesome. Thanks for this great helpful tool guys!! 2 thumbs up.

This product failed on the first hole. The chuck end spins independently from the bit end and pulls out. There is no obvious damage on either end. When the drill bit touches the material it stops spinning and does not cut. Terrible design.

Made installing Hardie Siding on an ICF house much easier using, 9 x 1-5/8 rock on screws. I saw some complaints of the holes being over sized, but in fact this made for easier installation and kept the screws from gripping and pushing the siding out as the screws engaged the studs.