Drilling Flagstone

[1990C4S]

My neighbors can't even lift my Hilti demolition hammer...and I would never let them try a chain saw.

[john70t]

Hard material + hammer action is a recipe for cracking.

Use smooth grinding action instead.
And the hp and lube (water even) to back it.

[1990C4S]

My 'new' Dewalt hammer drill with a 3/4" bit can drill the pavers, not quickly, but it can do it.

Drilling a sample on the grass I got a lot of breakout on the back side, so I can't push too hard. With the stones on a mortar bed I think I will be okay, but a broken paver will be a big problem, I'm not sure I want to drill the deck this way.

I am thinking I need to but several of these, and use water with no hammer action:

https://www.amazon.com/Inch-Diamond-Hole-Saw-Pilot-Drill/dp/B0D2WV62X9/ref=sxin_16_pa_sp_search_thematic_sspa?cv_ct_cx=3% 2F4%2Bdiamond%2Bdrill%2Bbit%2Bsds&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-1-6024b2a3-78e4-4fed-8fed-e1613be3bcce-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM

The diamond bit has the benefit of a much rounder hole also.

[1990C4S]

Here is the right way...which is what I need to do...here is the link set to the moment of truth.

https://youtu.be/hW6UdFjyuTk?t=199

Diamond core bit, 2x4 guide, SDS drill, two minutes per hole.

[908/930]

Lol, pretty sure I said that about 20 lines back, but I use 3/4 ply not 2x4. I can't open your link, the diamond hole saws I use have 5/8-11 thread so you would need a SDS or SDS plus, whatever your drill is to 5/8-11 adaptor.

[1990C4S]

I still need to work out the drill size. The inserts are oversized, the 'normal' install is drill 3/4 and drive the brass insert into the hole. It's at least 0.060" interference fit, which might work in cement, but I know that would crack my flagstone.

Now I think I need to drill on size (21mm) and use anchoring epoxy. Or turn some of the knurl off the anchors and drill 20mm). Either way, I don't think the interference fit is a good idea.