I wonder if he could get one from the stone countertop fabricators?, or have them come out to drill a hole.

sloyd, thanks for the tip. He did ask our stone fabricator but the fabricator said the largest bit he has is 2.25".
I guess it is because I have a quartz tub surround as opposed to the usual tile..
I will have to call up Hansgrohe customer service to ask.

amazon has them as well

Here is a link that might be useful: link

In the yellow pages - look up concrete hole drilling. I've had 6 / 8 / 10" holes drilled in concrete.

sloyd, thanks for the link! i guess my GC is old school. he only checked all of his building supply stores. amazon is great!

doug_gb, i will call up some concrete hole places if I can't find the drill bit for my GC. thank you!

" I've had 6 / 8 / 10" holes drilled in concrete."

I had to punt an exhaust vent for a large paint spray room through a 5 foot thick tool rim rated concrete floor.

The vent was 32 inches in diameter.

It only took about 24 hours of drilling with a huge core bit.

It took longer to erect the scaffold to hold the core up 35 feet to the floor below.
And another 8 hours or so to lower the core down to the 'basement' floor.
It took a lot of rounds on the chain hoist.

"And another 8 hours or so to lower the core down to the 'basement' floor."

It's not the fall, it's that sudden stop :)

brickeyee, sounds like tedious work!