Rotary Hammer Drill with Core bit

[Zemesis]

I need to drill several holes of a 6 inch hole in a wall of solid concrete about 9 inch thick. I am from southern europe and was considering Graphite 58G539 rotary hammer drill with a stand and safety clutch and buying some diamond bits.

However, this tool seems to be out of stock when searching for it online. Anyone knows of other solid alternatives that can do the job and not break the bank, ideally that can be bought in europe and shipped throughout the continent.

thanks

 

[BombShelter]

Welcome to the forum! I use the smaller Bosch RH328VC SDS Plus for drilling 1" dia holes (up to 18") all day long. I don't know how they'll do with core-drilling but the larger SDS Max Version might work better in your situation. All of our home stores stock the Bosch and it's still made in Germany.

 

[dnschmidt]

Hilti, when it comes to concrete they have the answer. Bosch is good, Makita is good, Milwaukee is good but the king of concrete is Hilti.

 

[Beerhippie]

Rent? This is exactly the kind of need that I'll rent tools for.

For several 6" holes, 9" deep, I'd look into a supported drill--one that works from an adjustable stand. A hammer drill held horizontally can get a bit heavy (and dangerous) after a while.

 

[KnurledNut]

“Several” can be 3 or 300 but I would rent a wall mounted drill.
Not really something you want to screw up.

 

[no704]

If it’s a one time job I would look into getting a pro to do it.

 

[signcrafter]

SDS+ is not going to be good for 6" diameter holes. You are going to want a core drill with a diamond core bit. And with a core bit that big you will want a stand. I've done 4" holes with a core drill without a stand in a floor and it wasn't fun. Not familiar with European building but guessing the wall will have rebar in it. I have a cheap core drill I bought off ebay or amazon over 10 years ago. I have only drilled a handful of holes with it so couldn't justify the much higher price of a name brand core drill.

https://www.aliexpress.com/item/1005006676442558.html?src=google&pdp_npi=4%40dis%21USD%21461.84%21173.64%21%21%21%21%21%40%2112000037993574721%21ppc%21%21%21&snps=y&src=google&albch=shopping&acnt=752-015-9270&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=_oDc8nzq&gclsrc=aw.ds&albagn=888888&ds_e_adid=775771422608&ds_e_matchtype=search&ds_e_device=c&ds_e_network=g&ds_e_product_group_id=2441360045959&ds_e_product_id=en3256806490127806&ds_e_product_merchant_id=5551326180&ds_e_product_country=US&ds_e_product_language=en&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=23046469188&albag=189807470550&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gad_campaignid=23046469188&gbraid=0AAAAA_eFwRARKj_FCI5SKwhKR20YrLnKf&gclid=CjwKCAjw0sfHBhB6EiwAQtv5qSXMaLiMzpkxdOvkWjhbK6gXZXm0moom9XTG2oibaaMr1Djp9eWAIBoCDnUQAvD_BwE&gatewayAdapt=4itemAdapt

 

[Beerhippie]

If it’s a one time job I would look into getting a pro to do it.

Don't just rent the tool, rent the tool and operator!

 

[sparky 1971]

I have a Bosch RH745 SDS Max, rated for up to a 5" core bit but the largest bit I've used was a 4" for one hole through an 8" wall. Never again; the drill worked fine but holding that damned thing for what seemed like an eternity while it beat me up was enough for me and I'm not a small person, quite the opposite actually. The RH1255VC is rated for a 6" but weights eight pounds more than mine and has to go deeper, as well as drill more than one hole. No thank you. There are companies out there that specialize in drilling large holes in concrete for a reason.

 

[Beerhippie]

Fusion lance. When enough isn't enough.

WTF is wrong with Google these days? Yeah, I know. Trying to find a picture of a simple fusion lance gets me nothing but video games.

A fusion lance--unless I have absolutely the wrong name for it (possible)--is an iron pipe filled with small iron rods, with O2 forced through. Ignite the tip with an oxy-fuel torch and you can drill through a major river dam. Yeah, the lance goes away at about the rate the bore goes through the concrete, but it's iron pipe and rods.

 

[LopezBart]

oxygen lance https://www.google.com/search?clien...ate=ive&vld=cid:38cf4696,vid:vqzJjOjThFc,st:0

 

[strength_and_power]

oxygen lance https://www.google.com/search?clien...ate=ive&vld=cid:38cf4696,vid:vqzJjOjThFc,st:0

I got to use one on a composite safe, ( steel, concrete with rebar etc in it and more steel), it gave zero F’s about what was in front of it.

I’ve also had to line up concrete coring/cutting companies to core a man size hole in a vault. Both times I was surprised at the cost, way less than what I was expecting. I’d get quotes on having it done, renting the equipment and your time to struggle with it.

 

[RTM]

Late to the party here, but if using a Diamond core drill, isn’t a hammer drill the wrong tool? I though the hammer function should be off for those tasks. But no one has mentioned that part so far. Am I missing something?

 

[Zemesis]

This Graphite 58G539 rotary hammer drill I had looked at, comes with a stand, thats why I was considering something like it and yes technically it's more of a core diamond drill that is needed. Some rebar might be in the way, but I will use a metal detector to potentially avoid these areas. What is important to me, that it has an automatic safety feature (clutch)

 

[Nobody-named-Olli]

- 2kg class SDS-plus rotary hammers are the wrong tool for this job, no matter the brand. Most of them feature a “safety clutch” and that will be engaging almost constantly when using 150mm diameter hole saws/ core bits in concrete, let alone reinforced concrete. Little too much pressure, or a little tilt (at these depths) and you’ll smoke that clutch in almost no time.

- Diamond core bit cutting requires fairly accurate speeds to get into that sweet spot of advancing/ cutting speed and tool life. When cutting dry, dust extraction is a must as it helps significantly with cooling. (Let alone all the other benefits …) Wet cutting is always a mess (without latest technology for water circulation) but would be the preferred method depending on concrete type, … .

- Never use ”hammer mode” with diamond hole saws/ core bits. There are diamond hole saws/ core bits that are compatible with what is called “soft hammering”, that is a special feature some core drills have - this is not comparable to use with rotary hammers in hammer mode.

- In fact, forget about hammering mode in general with this application. Even those cheap carbide tipped “hammer core bits” won’t do any good in concrete with this type of machine. See my first paragraph, it just smokes the clutch.

My advice is:

A) If you must DIY this on a budget: Chinese core drill with stand and either use dust extraction or water, depending on what machine you buy. It will do what you need to do and then some. Plenty of vendors/ sources online.

B) Rent machine locally if you can get this buttoned up within reasonable time.

C) Hire a pro and have this done in an hour or two tops. They will most likely not mess with setting a stand for 150mm diameter holes. (Which is what will cost you the most time with options A and B)


EDIT: In absence of a wall mounted stand, you can use a template screwed to the wall to make life a little easier for the first few centimeters in, once in this isn’t needed anymore.

- If you should decide to do without, tilt drill downwards, so only a small part of the hole saw/ core bit touches the concrete, carefully start drilling/cutting. Once you have a little notch in the concrete and positive engagement of the bit, slowly tilt upwards while drilling/cutting until square/ at the desired angle. Takes practice, but works.

Kind regards,
Olli

 

[98ssuck]

Depending on how many several is and the finished tolerances. Using a small SDS drill with a 3/8l bit following a drawn circle can get the penetrations done. Generally this leaves a rougher finish than the core bits.

 

[willf650]

I personally would just rent a core drill.

The graphite Drill that came up in a google search for me is about the smallest rotary hammer made and will not do a 6” hole.

I don’t think I’ve ever seen a core drill beyond 4” for a rotary hammer. If they make one it will be for a larger sds max or spline rotary hammer and that is not something the average person will use often enough to justify buying one.

 

[bluedog225]

SDS+ is not going to be good for 6" diameter holes. You are going to want a core drill with a diamond core bit. And with a core bit that big you will want a stand. I've done 4" holes with a core drill without a stand in a floor and it wasn't fun. Not familiar with European building but guessing the wall will have rebar in it. I have a cheap core drill I bought off ebay or amazon over 10 years ago. I have only drilled a handful of holes with it so couldn't justify the much higher price of a name brand core drill.

https://www.aliexpress.com/item/1005006676442558.html?src=google&pdp_npi=4%40dis%21USD%21461.84%21173.64%21%21%21%21%21%40%2112000037993574721%21ppc%21%21%21&snps=y&src=google&albch=shopping&acnt=752-015-9270&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=_oDc8nzq&gclsrc=aw.ds&albagn=888888&ds_e_adid=775771422608&ds_e_matchtype=search&ds_e_device=c&ds_e_network=g&ds_e_product_group_id=2441360045959&ds_e_product_id=en3256806490127806&ds_e_product_merchant_id=5551326180&ds_e_product_country=US&ds_e_product_language=en&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=23046469188&albag=189807470550&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gad_campaignid=23046469188&gbraid=0AAAAA_eFwRARKj_FCI5SKwhKR20YrLnKf&gclid=CjwKCAjw0sfHBhB6EiwAQtv5qSXMaLiMzpkxdOvkWjhbK6gXZXm0moom9XTG2oibaaMr1Djp9eWAIBoCDnUQAvD_BwE&gatewayAdapt=4itemAdapt

That’s a tempting price. I can’t imagine it will work out well though.

Would anyone take a chance on this?

 

[tiredoldironworker]

When we are setting handrail or guardrail posts with Porok we have had good success with SDS-MAX rotary hammers and dry cutting carbide core bits in 3 to 5 inch diameters that look like oversized hole saws. You can only get about 3 to 4 inches then have to break the core out and go deeper. Having a vacuum close to the hole makes for minimum cleanup. We do NOT like the slurry created by regular wet coring bits. They always stain the surrounding surfaces. For vertical holes we don't use a stand and have had no issues. Just go slow!

 

[neophyte]

You might be better off looking for a used unit made by an actual “Industrial” tool manufacturer.
Admittedly, the resale market varies by country, so deals might not be available, but high end industrial equipment tends to be made to last.
A 6” hole in concrete is not something I would do with a basic hand held rotary hammer.
This type of hole is usually done with a slow motored, drill without hammer function.
I have no clue what country you are in, or what brands are available, but the “Industrial” standards for drolls for this type of work are Hilti, Duss, Bosch, Eibenstock, FLEX (from Germany), Weka, Kango (now owned by Milwaukee and probably branded as such), and Husqvarna.
Fein used to manufacture Core Drills and motors with stands, but I think stopped doing so, so people might be less likely to know about the units.
AEG, now owned by the same company as Milwaukee likely manufactured units as well.
Makita, Hitachi, also manufactured masonry core drills.
Sparky, made in Bulgaria, might be another option. Bosch I believe is or was rebranding some Sparky tools.
The Graphite drill you specified looks closer to the type of drill one would use for SDS drilling smaller holes in concrete.

 

[Nobody-named-Olli]

For Europe I would strongly advise to stay away from used Hilti tools as far as you possibly can.

The amount of ridden to death, construction site abused, tools that are then fixed with cheapest possible parts and sold as “refurbished” is enormous and at the end of the day not at all worth the prices they still fetch because “Hilti” …

Hilti is not a consumer product here, OEM spare parts available through Hilti only - or grossly overpriced through third parties - and not every Hilti point of sales will deal with walk-ins.

And again, besides standard parts, it’s hard to tell genuine OEM parts from cheap overseas imports.

Buying used Hilti online in Europe = shark tank.

Also Hilti are probably the #1 in terms of stolen tools. If you ever bring in a tool to Hilti, that they have on their blacklist (because you can’t service it yourself/ or get the parts and if you have a point of sales that will deal with you), you’re in for a lot fun.

Buyer beware, stay away!

Not to mention that none of this is going to happen on that “Graphite rotary hammer”-budget anyway. Even the Chinese machines are already a stretch, but at least they will get this done without additional headaches for a DIYer’s one time job.

Kind regards,
Olli