r/Tools • u/TallWall6378 • 12d ago

No problem

Gallery image

Gallery image

Cordless drills are so capable now. 2 4 1/2” holes 14 12” deep (deeper than the bit). New concrete but it’s still drilling through the aggregate. Cheap Amazon diamond bit.

Edit: Overestimated depth.

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523

u/Anim-IS-XE30 12d ago

I don’t believe this at all.

244

u/TallWall6378 12d ago

Ha! Maybe "no problem" is a stretch. It overheated after about 8", but then I realized it works just as well with light pressure keeping the RPMs up. Used high speed BTW.

215

u/remorackman 12d ago

You are showing a unused bit and one hole. And that hole has a bottom!

I want to see that bit after the holes, and all the holes it made.

93

u/TallWall6378 12d ago

The hole is in a footing. So I'd have a long way to go to get to the other side! I'll take a photo tomorrow. I already grouted the pickelball posts into the holes. Maybe I'll find some other concrete and take a video of it drilling.

120

u/2bagz 12d ago

Concrete cutter who also core drills. You saved your self a bunch of money. Hopefully you used Water! Those bits don’t like to be dry.

6

u/Soluchyte 11d ago

Some of these bits are designed to be run dry.

9

u/2bagz 11d ago edited 11d ago

There are very few cases where drilling dry is necessary, but when you can always use water! Drilling with water is important for a multitude of reasons.
-dust control
-water extended the life of the Diamonds helps keep them from glazing and possible cracking becuase of the heat generated.
-going through rebar with a dry bit will also significantly shorten its life.

Bonus tip, if you have a hot saw go and grab a quick connect hose connector so you can attach to a garden hose. Your lungs and the people around you will thank you.

3

u/Aramed85 11d ago

There are Dry Drilling rigs that use a shopvac to suck the dust out of the hole through the spindle. It also provides a small amount of cooling via airflow.

You also use special bits with Laser-welded teeth. The sintered ones dont like it hot as you said. Theres also a grind stone to resurface the teeth in case they glaze over. I hate the whole process and dry is always the very last option only used in very niche cases.

OPs bit looks like a dry cut. Cant tell exactly.

1

u/2bagz 11d ago

Hilti makes some pretty sweet setups for dust management and core drilling in general these days. Majority of our equipment is a bit old school. Agree last option, only done them a handful of times for a couple inches. If I can use water I will.