Drill Review: Bosh 18V RHH-181

Hey all!

Thought I would put in my two cents on a newer drill I just purchased!

For starters, I have been developing on and off for a few years now and have used several drills including the new, compact 36V Bosch (bitchin!), an 18V Makita (better than expected), 20V Dewalt (way better than expected), and an old Bosch 24V Annihilator (......heavy). I felt as though I had a good feel for what I wanted when I finally purchased my own. My main concerns were being able to get 20 + holes per battery which would suffice for my use, and to have a good balance between light weight and heavy enough for my application.

I develop exclusively on Bighorn Dolomite. Most of the time it is very hard, however occasionally it has a hard 1" crust and a spongy core.

After obsessive research, I decided to go with the Bosch RHH181, a newer 18V option from Bosch. I purchased it from CPO outlets, and chose to go refurbished. REFURBISHED IS THE WAY TO GO! Most of the time, refurbished power tools simply had batteries that did not function properly when the tool was originally sold. They simply put it in new packaging with good batteries and send it out. Mine showed up and I couldn't even tell it had been used. I paid $350

I took it out to a new crag here in Lander and got to work on some routes. The drill bores super quickly in our stone and the time per hole was only slightly longer than the 36V Bosch (almost unnoticeable). I ended up flipping over a boulder to see how many holes I could get on one battery. It got to the point after 18+ holes that I was sick of drilling and came to the conclusion that my goal of getting at least 20 per battery was easily attainable. For limestone, this drill is the shitttttt.

One of the best parts of the 18V Bosch is that it is FUCKIN LIGHT!!! I didn't even notice it in the pack. On a scale, it comes in at a little under 5 pounds.....crazy. For a drill this light and inexpensive, it really packs a punch for its size.

While a 36V would be nice for hardrock and large, deep (4in plus...) holes, the 18V is a great option for developing on softer stones and for those of us with shallower pockets!

Cheers!

Thx for posting.

lots of good info Thanks for taking the time. I have a few questions about the drill. how big are the hole that you did on your test, 1/2 or 3/8 and how deep? I am in the Arkansas Ozarks common practice now is 1/2 and about 4" deep. I got the new bulldog36volt drill but it is heavy as F*ck so I returned it and need to get a lighter drill. It sound like this is the one. Thanks for any input you may have.

I didn't get a chance to drill any 1/2 in holes due to the fact that my bit went missing....

However, the holes I was drilling were 3/8 and ~4in. deep. It does great after the first two inches, the only bogging down is due to the fact that the bit can't move material fast enough. I don't think 1/2 holes would be a problem. And if you're seeking light weight, this thing is the shit! A perfect balance between power and bulkiness. Good luck!

Great thanks,
Cheers

Long Term Review!

I've been drilling quite a few 3/8 holes with this drill, and never had it bog down. I replaced a bunch of old 3/8 rawls with 1/2 stainless powers 5 pieces today in Sinks Canyon, WYO and got to drill quite a few holes! This drill performed great still. I drilled 10, 1/2in x ~3in deep holes on one battery and it had the juice for more. It probably took a little longer to drill them as deep as I would like, but nothing crazy.

Needless to say, I'm still super happy with this purchase. It's not as chincy as the light duty Milwaukee, but I haven't felt like I should have went for the 36V once yet.

TSpiegelberg wrote: Hey all! Thought I would put in my two cents on a newer drill I just purchased! For starters, I have been developing on and off for a few years now and have used several drills including the new, compact 36V Bosch (bitchin!), an 18V Makita (better than expected), 20V Dewalt (way better than expected), and an old Bosch 24V Annihilator (......heavy). I felt as though I had a good feel for what I wanted when I finally purchased my own. My main concerns were being able to get 20 + holes per battery which would suffice for my use, and to have a good balance between light weight and heavy enough for my application. I develop exclusively on Bighorn Dolomite. Most of the time it is very hard, however occasionally it has a hard 1" crust and a spongy core. After obsessive research, I decided to go with the Bosch RHH181, a newer 18V option from Bosch. I purchased it from CPO outlets, and chose to go refurbished. REFURBISHED IS THE WAY TO GO! Most of the time, refurbished power tools simply had batteries that did not function properly when the tool was originally sold. They simply put it in new packaging with good batteries and send it out. Mine showed up and I couldn't even tell it had been used. I paid $350 I took it out to a new crag here in Lander and got to work on some routes. The drill bores super quickly in our stone and the time per hole was only slightly longer than the 36V Bosch (almost unnoticeable). I ended up flipping over a boulder to see how many holes I could get on one battery. It got to the point after 18+ holes that I was sick of drilling and came to the conclusion that my goal of getting at least 20 per battery was easily attainable. For limestone, this drill is the shitttttt. One of the best parts of the 18V Bosch is that it is FUCKIN LIGHT!!! I didn't even notice it in the pack. On a scale, it comes in at a little under 5 pounds.....crazy. For a drill this light and inexpensive, it really packs a punch for its size. While a 36V would be nice for hardrock and large, deep (4in plus...) holes, the 18V is a great option for developing on softer stones and for those of us with shallower pockets! Cheers!

The Bosch model in your review is an excellent drill and I switched from having used Hilti.

Comparison review at the link below;

https://francishaden.wordpress.com/2016/02/13/drills-for-bolting/

Nice review man! Just got back from a trip where I was drilling 4 inch x 1/2in holes for Climb Tech Wavebolts. The longest route I put up involved 8 holes and my Bosch still had more juice left on the one battery. I'm so psyched on this purchase, and let me say it again, I went with the refurbished one!! I've put close to 100 bolts in the wall with this now and it's been perfect!

Does anyone have an idea of how an 18 V Bosch would handle really big holes, like 5/8" or 3/4", in softer rock? 

Jonathan Croom wrote:

Does anyone have an idea of how an 18 V Bosch would handle really big holes, like 5/8" or 3/4", in softer rock? 

Metrically speaking a 16mm or shocker; 19 / 20mm hole.

16mm no problem really, I've installed 150mm (6") deep Bolt Products glue-in bolts in granite no problems at all drilling a hole of that diameter and depth.

Titanium bolts I regularly place take a 14mm hole and that's typically drilled i volcanic tuff, another hard rock.

Drilling in limestone is like talc by comparison, regardless of the diameter you would need to work with.

Curious as to what you place with a ¾ inch diameter hole?!

The key point though is using the high capacity batteries (6 Amp) to ensure you have comparable RUN TIME against larger, higher voltage drills.

Just got mine in the mail yesterday and was surprised by how powerful it was. Drilled a couple of 1/2" holes with ease into some blocks in my front yard. One block was limestone and one was some really hard quartzite. Not sure about larger holes but seems like it would do just fine, particularly with soft rock. 

Cool, thanks for the replies. I'm considering buying a root hammer for occasional use, and probably more for highline anchors than for climbing. There are some cool potential highlines close to where I'm moving, but completely abysmal rock quality. Not sure whether it will be a viable idea yet. So I'd only need 8 holes total per line, and it would be easy for me to split it up into a day for each side so half of that. I just don't want to get a drill that can't even get started if I decide to put in some massive bolts, but I don't mind drilling only a couple per charge.

Jonathan Croom wrote:

Cool, thanks for the replies. I'm considering buying a root hammer for occasional use, and probably more for highline anchors than for climbing. There are some cool potential highlines close to where I'm moving, but completely abysmal rock quality. Not sure whether it will be a viable idea yet. So I'd only need 8 holes total per line, and it would be easy for me to split it up into a day for each side so half of that. I just don't want to get a drill that can't even get started if I decide to put in some massive bolts, but I don't mind drilling only a couple per charge.

Ah ok.

Just as an aside, and not knowing your own experience, thus not wishing to lecture...if you place two bolts that have the same embedment depth but one is a thicker bolt then sure, the the thicker bolt will be stronger. But, taking the original smaller bolt and using a slightly longer embedment, is actually stronger than using a larger diameter bolt drilled to the original embedment depth. It's also easier because you are drilling the same diameter holes, just longer and will draw less energy from the drill. If the rock is weak you definitely want to be placing glue-ins and practically you will only find longer, off the shelf, products for glue-ins, well certainly out of Europe. Contact Jim at Bolt Products Germany (google the site) - he posts on here regularly anyway.

Some math;

Uniform Bond Stress Model:

N = B(pi)(d)hef

Where:

N = bond strength (N)

B = bond stress for the adhesive (N/mm²)

pi = 3.142

d = hole diameter (mm)

hef = anchor embedment depth (mm)

Based on an online value of bond stress found for Hilti RE 500 epoxy at 12.4N/mm² and a 12mm hole, drilled 80mm deep we get:

N = 12.4 x 3.142 x 12 x 80 = 37,402N or 37,4kN

If we increase the hole depth to 100mm then:

N = 12.4 x 3.142 x 12 x 100 = 46,752N or 46,8kN

Which is a larger increase in strength compared to original embedment depth but larger hole diameter:

N = 12.4 x 3.142 x 14 x 80 = 43,636N or 43,6kN

Drilling a similar diameter, but longer hole is certainly preferable than carrying two drill bit and bolt sizes.

https://francishaden.wordpress.com

Read this review, i hope its batter

Hammer Drill Review

t.farrell wrote:

If you're not drilling a ton of holes, might be worth looking into the hammer drill version of this drill (Bosch HDH 181x). I bought one today for light use around the house. Granted I was drilling small holes, but I was doing 3/16" holes 6cm deep in under 15 seconds (pre-war concrete). I'm really happy with it and like that it has a standard keyless 1/2" chuck (as opposed to an SDS...) so it can be used with some more standard drill bits and drivers around the house. 

Got it brand new on Amazon for $220 and same day delivery. Came with two fat pack 4A batteries.

Hammer drills are fairly useless in hard rock with larger bits. I had the biggest, baddest 36v version that Bosch made at the time I bought it and it took me 15 minutes to drill one 1/2" x 4" hole in hard rock. You need a rotary hammer drill with an SDS chuck. Standard hammer drills just dont work unless you're bolting really soft sandstone and you only need to place a couple of bolts (a couple total, not a couple at a time).

http://newsok.com/article/3454189

Thanks for the informative reply Francis, I was not familiar with that equation. However, as a physics major I appreciate the equations and quantitative results, and will certainly use it to inform my decision. 

Jonathan Croom wrote:

Thanks for the informative reply Francis, I was not familiar with that equation. However, as a physics major I appreciate the equations and quantitate results, and will certainly use it to inform my decision. 

Cheers Jonathan

American Concrete Institute formula that can be found on Jim's website with pdfs and links online under design and behaviour of grouted anchors under tensile stress that cover the same formula.