Hammer drill vs. rotary hammer

[@davidsmithey8914]

Eleven years later (5.26.2023) and this video is still the most helpful one I have found on the subject!!! Thanks for posting it.

[@josephastier7421]

I finally ordered a pair of those shorts and gave them a try. My hammer drill worked about the same, but I was able to finish the job in a fraction of the time because my neighbors kept stopping by and offering to help. Nice guys!

[@renubisht8072]

Fghsdjiig

[@brandyprice7578]

Omg lol. I read this 3 times before the video actually started and I did not understand until watching the video 🤣

[@windymeadowsoxteam7783]

Need the sneaks too to really kick it up a notch

[@jonphanspromotions]

Where can I get those shorts? Nice video man.

[@alla6747]

@@brandyprice7578 KO l la

[@GuyFromJupiter]

A rotary hammer is basically a small jack hammer combined with a drill. The hammering is completely independent from the rotation, and it is quite powerful. A hammer drill is a drill with cams around the chuck to make it bounce and "hammer" the surface you are drilling when it rotates. The impacts are much less energetic than those from a rotary hammer.

[@MsSomeonenew]

For future reference to everyone on what the difference is. Impact drilling does not cut material as regular drilling does, all the front end of an impact drill does is bash into the material to dislodge a piece which then gets cleared out by the spiral. So the absolutely primary part of this process is impact force. Which is where a mere drill has problems as they only put a small toothed disk in there that generates small vibrations, where as the rotary drill has a huge chunk of metal getting smashed along the shaft. The drill might do something with soft/small particle masonry, but the moment you reach a harder piece it hasn't got the impact force to hammer out material.

[@muddyriverdogz]

2 different tools for 2 different purposes. If you want a 1/2 chuck with hammer capabilities but are not drilling through rock often a hammer drill is the way to go. If all you are doing is drilling rock then a rotary is what you want.

[@jimfoster7986]

I’m drilling into an inch thick blue stone capstone so I can run a wire to a lamp. Which is best for this job? The hammer or the rotary?

[@cisco1007]

Rotary always especially through brick. Some are harder than rock no kidding!

[@michealfemino5079]

One of the more straightforward and concise tool demos I've seen anywhere. Told me what I needed to know, thanx much!

[@budzcee]

This video was simple, yet very useful. I'm doing some training for work, and I'm reading up on different hammer drills and rotary hammers. Seeing you use the two tools gave me a lot of insight, and will be able to help customers more now that I've seen a demonstration. Thanks a lot.

[@dzeledonzeledon5843]

11 years later and you probably got best straight forward explanation I watched online. Cheers

[@imnotjacob.]

Found this video while looking for a hammer drill. Finished the video, and ordered a Rotary Hammer Drill instead 😄I didn't even know this tool existed until about 5 minutes ago. Thanks mate! saved me buying the wrong thing.

[@jessihawkins9116]

didn’t know 😆

[@GrantHackethorn]

This might be the best commercial for a rotary hammer I've seen.

[@zarrow50]

But that is what rotary hammers are for, drilling into concrete.

[@theone4412]

Clive Ellis Pretty much to to extend productivity

[@ximmeh1987]

Lol

[@zookini33]

I was looking to buy a hammer drill but I am now convinced that a rotary hammer would be a better choice for me. Your demonstration made this very clear. Thank you!

[@muddyriverdogz]

Depends on what you are doing with it.

[@davidswanson5669]

7 years later and now I’m being informed enough to realize I need the rotary hammer. Glad I didn’t open the box of the new hammer drill I just got.

[@nicholasmcvay]

Great Job on the demonstration

[@AuthenTech]

Wow, wish I saw this yesterday before drilling those holes in my brick - my hammer drill took FOREVER on just a few holes. Thanks for sharing!

[@originalSoaren]

Did you have your bit all the way against the back of the chuck? If not the hammer won't tap the bit

[@merlinmage6012]

You used hammer bit? Designed for hammering cant use regular bits meant for drilling wood and metals.

[@beedebawng2556]

Very very very useful video. I wish more content uploaders had more respect for their audience as you clearly do. No self-indulgent waffling. Just useful information. Thank you very much.

[@mitch_smith]

Bud you just saved me about 150 bucks and some serious headaches. I appreciate you.

[@kristianrmitev]

I was asking myself the same question and researching online came across your comparison. Thank you for adding to the collective knowledge of the internet. Extremely eye opening, seeing the difference.

[@ZezimaTruth]

Folks who come up with designs for these tools & engineers who find ways to build them to make our lives so much easier are awesome.

[@josephaguirre6123]

The shorts are lit

[@hackiehackerson]

Lmao

[@cal8338]

Pair that with romper and were set

[@johnnydept4082]

Lmmfao

[@djocho1]

Great legs man!! And the video was super helpful too!! Thanks!

[@Puck90a]

I once tried drilling a one inch hole in a dense concrete slab with my Dewalt hammer drill, and it took me over an hour if I recall. It took me forever to get about 1-2" deep. I finally gave up and went down to a 3/8" bit and FINALLY got through, and going back to the 1" bit took me another good while (seems like a bad idea, because doing that would eliminate the pointed tip of the bit from having it's penetrating action). I can't believe the drill didn't catch on fire before I was done (I quit about every 30-60 seconds to try to let it cool off, which made the job take much longer). It still works, but I use it for smaller jobs. And yeah - that one inch bit was PURPLE when I was done. Wish I had seen t his video before I bought that hammer drill... Live and learn.

[@wintermachine]

drill a 1/4" pilot hole first. Then drill your !' hole. You may find it will cut your time down to 10-15minutes.

[@gpcm9226]

Side by side reviews are the best. Good work

[@simpleman283]

You can also get chisel bits for rotary hammer for removing tile.

[@JillofAllTrades2]

Exactly what I needed to know--I'm going out first thing in the morning to add to my tools. The hammer drill took WAY TOO long to drill through some concrete tonight.

[@Beyllion]

I desperately was trying to drill a 3" hole in a concrete wall with a Bosch hammer drill until I gave up and went to buy a basic Lidl rotary hammer. Best décision ever.

[@oaktuber]

Great informative video. I need to drill some holes in concrete so I can secure a post to an existing slab of 6" thick concrete. Very helpful, good video quality and narration

[@davidcosine]

Same experience. I bought a large corded Ryobi hammer drill and it sucked. Borrowed my electrician friends compact cordless rotary hammer and it drilled holes in concrete all day. The other couldn't do one

[@arashheirani7003]

Very good and informative demonstration. Thank you.

[@Tbvck]

That was a very good comparison of the 2 drills. Thanks

[@nalramroop4641]

The hammer drill is a multipurpose tool for smaller jobs. The comparison is null

[@sarahrosen9272]

Hammer drill: A drill that has a small impact mechanism. Useful for drilling small holes in brick, cinder block and other softer materials. Rotary hammer: A demolition hammer with a rotating bit. Useful for drilling up to 2 inch holes in hard materials including concrete, granite e.t.c.

[@markwon8945]

Thank you for this tidbit of info. It really helps to understand which situation is best for either tool.

[@jules2957]

Thanks

[@svenschindler2336]

Not every rotary hammer is meant for demolition. The smallest ones have 1.7 Joule of energy, a proper demolition hammer has 7.5 Joule and up.

[@Mentorcase]

Rotary hammers like magic, when I got mine I tried the 25mm bit in concrete and it it just fell through it, I had to drill a few more holes to make sure it wasn't a bad bit of concrete but nope it is fearless with concrete also it will go through reo bar just have to take it easy so it doesn't deflect but it still chews through anyway. We tried drilling hundreds of holes through the edge of some concrete to fit reo bar for a joint with a makita hammer drill and after 2 holes decided

[@Munene-1]

You're the best coach and you're experience is real

[@donkmeister]

Great comparison! I bought a Hitachi SDS 8 years ago as a treat to myself, and it's still going strong (metal gearbox, not the cheapo one). Over the years I have lent it to various friends and family, and every single one of them ends up buying their own SDS shortly after. I honestly can't understand why there are still regular hammer drills available.

[@jessihawkins9116]

i bought a hart 20v hammer drill

[@rockyslack799]

2:12 "One of the best holes I've drilled!!"...slogan of the decade.

[@dzigizord6567]

brother was surprised how good of a hole he drilled so he wanted to drill a worse one next

[@andyprairiedog]

I finally calmed down after reading some "Larry Bird shorts" comments and the youtuber responding with saying his wife said he should be embarrassed for uploading this video. Some funny stuff and humor the up loader has.... With that aside, thank you very much for the comparison between the 2 types of concrete hole makers. I believe the rotary hammer is the way to go for my intended applications. Even in 2019, "vs" videos barely came out about 1 year ago. Thanks a bundle, sir.

[@jrsforest187]

I just bought a hammer drill, now I can see I really needed a rotary hammer.

[@ElmoIsBold]

@bahathir Thanks much for your video response. My one regret regarding my video is that I was unable to hit the aggregate that plagued me while working on the actual basement walls. When I DID hit a piece of granite river rock in the foundation wall my progress was often literally stopped until I hammered and punched it with a long slender cold chisel. My video makes the two devices look nearly equal, when in reality the hammer drill is a door stop unless drilling cinder block. Excellent demo!

[@TheEffectofMaverick]

Hammer Drill : light weight, compact, easy to transport to different jobs and use around the job site. Versatile - can be used for small - medium size holes (can bore large holes if you progress from smaller to medium to larger) through many different material surfaces with minimal risk to damage of home or property. Sds rotary drill : heavy, more durable, more powerful and robust - specializes in masonry/concrete drilling, good for boring large holes, over and over again. Usually used in construction work/heavy duty drilling where you need to drill multiple holes. Not versatile as far as doing more delicate or intricate, smaller holes on more fragile material.

[@nalramroop4641]

Yea its multi purpose.

[@mikespencer2972]

Happy 17th anniversary on uploading this video. Over a million views! Cheers! (good video, rotary hammers are no joke)

[@Arfonfree]

I would emphasize how clean the holes are. It makes a big difference in how secure the anchors are. Also SDS drills are available in much longer lengths which can be a big help for your back when drilling the floor.

[@MrLuigi77047]

This video is a masterpiece 👏. Exactly the information that I was looking for. I am mounting a toilet and needed only to drill two holes in concrete. I have a hammer drill, but it will not drill the aggregate . I need the holses in a certain place to line up with holes in the toilet. . I previously rigged it because my hammer drill sucks. My rig lasted twenty years, but it is leaking now. I know I can drill my holes with a rotary hammer drill. Thanks for making this video. No one else has shared this information. Great job 👏

[@InmortalMe]

This is exactly what I needed, just bought a house made of mostly concrete!

[@Pinchshot39]

I spent 2 hours drilling 4 little holes last weekend. Should have watched this 1st.

[@dougankrum3328]

Nice video, I've used both of these tools and for drilling concrete, the "more hammer....less drilling" is the only way to go. As a millwright....there were days I installed 2-3 THOUsand concrete anchors...big warehouses with many Pallet Racks...Here in Calif...all Pallet racks must be anchored for seismic requirements...(earthquakes)....the high-speed 'drills' are also good at melting the silver solder and losing the tungsten-carbide tips....

[@windymeadowsoxteam7783]

You were probably working a 10 hour day. A bolt installed every 12 seconds is still smoking, no wonder you were melting bits. Did you switch drills off or just run em till they smoked?

[@dougankrum3328]

@@windymeadowsoxteam7783 OK, I guess I should have checked my reply better....a hundred to 200 a day. one to two boxes of 100 anchors...3/8" and I drilled them to maybe 2-2 1/2". Big BOSCH SDS roto-hammer.

[@20danieldennis]

Wow that just settled my decision. I was looking at CPO Outlet's Malwaukee Heavy Duty hammer drill vs the 7A Rotary hammer for a bit more and was wondering how they match up when drilling concrete. Thanks a billion for the video!!!

[@timm439]

Counted the time for each: 30 seconds for hammer drill 12 seconds for rotary hammer

[@edinfific2576]

What you didn't count was the amount of force needed to push the hammer drill vs. the significantly smaller force needed for the rotary hammer drill.

[@phychmasher]

@@edinfific2576 I'm about to hop in my time machine and let this fool know he should be measuring the FORCE as well!

[@jessihawkins9116]

@@edinfific2576 yeah he didn’t count that

[@macplastering]

nice demo man a clear winner on this test was the milwaukee

[@carlbeauregard5862]

If you clear the dust out occasionally as you drill, it won't bind and spin on you, and you won't have to pull so hard to get the bit out of the hole.

[@Bigchuck678]

Great video, but those 80's Larry Bird / John Stockton booty shorts are killing me!! Lol

[@f.demascio1857]

really tho...

[@jasonshoup4213]

hey man! it was 2011 when he did this; fashion was a whole different world back then :)

[@ACommenterOnYouTube]

in 2011 i was 37 and was NOT wearing short shorts .. EVER ...

[@daviddabossbailey]

😂😂😂😂😂

[@feorh1919]

he got a nice pair of legs - why bother?

[@kellyandcorygingras7147]

Great video! I've spent many wasted hours with a hammer drill and concrete. Sprained my neck last time, too! Ordered a rotary hammer last night. Regular $1050 on clearance sale to $380. Cant wait to get it and save my back, neck, elbow, shoulder....

[@ClassyOldMusic]

Good Day! I hope you're enjoying a pleasant one. At about 1:20 where you advise about letting the machine have a good bounce. I used to restore vintage power tools, going back to the early 1900's, and some came with original instructions. More than once the Ol' Timey Instruction authors, while writing about how much pressure to use with the machine in question, power drills, saws, and such, advised to use just the right amount of pressure to let the tool do the work, and also warned not to "Crowd" the tool. I feel pretty certain you didn't pay a pile of money for your power tool so you can get a stiff muscle somewhere while trying to Force (Crowd) the machine, and not allow it to do the work for you. This video is my first introduction regarding the usefulness of the Rotary Hammer. I like it, and believe it to be an Excellent demonstration. Thank You for taking the time to create and post it. Enjoy! ~ john b.

[@Jacobe]

Thanks for sharing. That rotary hammer drill is a beauty.

[@BM-jw7pe]

Thanks for the video. It helped me to decide to spend the extra money and buy a third drill.

[@ankhesenamun4707]

As a leg fan and a leg lover, I would say that these are the prettiest legs I have ever seen.

[@handyman7297]

Are you male or female ?

[@AK-47ISTHEWAY]

@@handyman7297 Hermaphrodite

[@Mixwell1983]

Thanks for the video, i have a big old makita hammer drill and i just opened up a case i had in the garage of an aeg roto hammer and didnt know the diff. They aeg makes the big makita look not soo big. These were all my grandpas tools as he was a general contractor and has since passed but going through the garage i find all sorts of tools. My makita is same size as your dewalt and the aeg is huge like your roto

[@SiliconPrairie]

This is my uncle. He's like this in real life too.

[@MohdAsriOthman]

oh this explained why it took me so much times to drill a hole, my hammer drill just doesn't work on concrete

[@thesage1096]

can vouch for this. had to put in some base boards around some cinder block walls. got one of those type of drills...and well yeah a rotary happer for cinder wall with 1/2" plaster is like going to a gun fight with an 80mm artillery cannon. but man it was a pleasure to use.

[@thesage1096]

also give the drill and chisle some real work breaking up a foundation block. work like a charm.

[@rafaeldeleon225]

The struggles explained👍

[@hds181]

Has anyone else noticed the the rotary hammer is 3 times the size of the hammer drill? Sheer physics would indicate that it would go through faster under its own weight with equal drill bits, pushing or not.

[@CaesarREDNYC]

Thank you. I've been searching for this video for weeks.

[@zoltizolti3165]

What old drill is werry strong constructions for hard working Hitachi, hilti, metabo or usa and soviet models? And verry strong components have?

[@TrauCau]

I feel so dump. I always thought rotary drill is for wood & drywall, and hammer drill is for concrete. Your video really proves me wrong.

[@heroknaderi]

The rotary hammer best especially for major jobs

[@MrRoberoni117]

Thank you for this video. You've saved me hours of labor. Rob

[@dorkytourist]

Wow, this is a nice lesson and a convincing comparison. Gonna go shopping . . . Thank you!

[@arcturusbbqsausagemaking2435]

Thanks im trying to drill 4 =5/8 holesto mount a harbor freight metal bender and im pulling my hair out trying to drill into the concrete i have it mounted on wood now need to go into the concrete ?

[@geoffhess2267]

Excellent video. Bought a Craftsman 1/2 in. corded drill/hammer drill thinking that I could drill into my basement and garage concrete walls. Exactly as you showed, once into aggregate, it's not going anywhere! Going to get an SDS hammer drill.

[@charlesforeman9438]

Put this in slow motion and watch the chuck on the yellow drill first it's going in reverse as it struggles to drill, no wonder the other drill went through like butter as it was going the proper direction

[@fungi8pho]

Adjust the front handle to 90 degree to the trigger handle for a better hold... the way you have it is for transportation or storage.

[@mattdouglas8900]

This is my submachine hammer gun

[@frankalarcon635]

Great video comparison! Im in the middle of drilling with my Bosch hammer drill into some concrete wall to put up some shelves and have spent over 2 hours for 6 holes!! and to make it worse 3 of the holes are oversize and the bolt anchors struggles to do up tight... I need a Rotary Hammer Drill!!

[@rumlad1]

Its not the speed of the drill but the blow force of the impact on the drill bit that counts. Measured in joules

[@CampaholicsTV]

He sounds a little like Beavis. Thanks for the info and video! I'm wall mounting a massive tv and now I know I'm going with the rotary!! Thx brother

[@danbremer7010]

Jimmy Lee Motta Beavis would like to drill some holes and stuff.

[@willd0g]

I wanna know what cut that aggregate concrete as well!

[@AK-47ISTHEWAY]

Most likely a diamond tipped concrete saw of some sort

[@noel888]

Great video...wonder if you could assist this 87 year old man who wants to drill a hole in my door hinge which needs a larger screw. its an old pre hung door so through the years the top hinge has messed up with the one inch screw they installed. I want to drill a hole deep enough to get past a 1/2" wood jamb, some concrete which was made for the opening of the wall to install the door and then comes the house brick. I would need to put an anchor into that brick for the screw, I was told. Could you suggest what to get for a one time job? Thanks

[@ElmoIsBold]

If there is no aggregate in the concrete, and if it's young, and especially if it wasn't made of the harder types, then a hammer drill might work for you. The hammer drill would more likely be the tool that would be more useful around the house in general than a rotary hammer, cost you less, and be more easily found at Home Depot/Lowes, etc. But if the concrete is harder, thicker, has aggregate, whatever, and proves difficult for a hammer drill, then a rotary hammer with the appropriate bit size will make the hole you need through the concrete. It might destroy the brick if you take the bit that far, though. I like the Tapcon screws for brick or mortar. The rotary hammer will probably cost you more. Also, rebar WILL stop any carbide bit, so use any tools at your disposal, including your wit, to avoid that situation.

[@kennethlarsen4657]

Anthony rrr

[@btf_jaytee4447]

how often are you supposed to clean the inside of hammer drills?

[@bigrig55555]

My hammer drill has a a round dial on the trigger. What exactly is that for? Please be specific. Thank you

[@noel888]

I accidentally deleted your response. ..wonder if you could send me that link again.? Thank you

[@embrj1453]

That's the same experience i had, the only probably with rotatory drills is that they do not give a clean hole, in other words, if you want to drill a hole all the way trough it will come out with a chunk of concrete...

[@johnlacambra6004]

4:39... When you play off the wrist twister as if it didn't hurt at all to keep a manly reputation amongs other old school short short wearing craftsmen.

[@pepperdog3761]

another example of "right tool for the right job"

[@ElmoIsBold]

Okay, make that "one turns somewhat while mostly pounding, and the other pounds somewhat while mostly turning."

[@EjaxPlus]

This is my second time coming to this video after a year, it was flawless last time with a hammer drill. This time I'm stuck with 3 holes against an aggregate using the same hammer drill and getting concerned with my hands getting tremors. Time to invest on a rotary hammer 💰

[@davidsandoval1697]

great video! EXACTLY what i needed to know! i just started drilling into a concrete slab in my back yard with my regualr cobalt drill. took forever!!

[@MarbledPaladin]

Are there rules as to how big a hole can be compared to the rest of the are you are drilling (for a wood beam it's not more than a 1/3) and are there any precautions to take with old concrete?

[@ElmoIsBold]

MarbledPaladin Your question is worded strangely, but I'll assume you're asking how big the hole should be relative to the anchor bolt. In my case - channel and angle beams bolted to the poured foundation wall to ensure stability prior to cutting window openings - they were the same: 1/2" drill bit for 1/2" Hilti bolt. The engineer called for this. My guess is that a 1/2" Hilti bolt is called that because it anchors into a 1/2" drilled hole. If you're doing your own personal work, and no engineers were involved as they would be for a public project, then I'd guess that you're probably going to use the same size drill bit as the nominal size of the concrete anchor bolt. It sounds like you're thinking of holes in hardwood for either some kind of wood anchor or a large nail. That's called a "pilot hole" and does not apply here. For old concrete consider (or find out) what else might be in the concrete, like rebar or aggregate. Other than that, and the fact that old concrete might be harder than modern concrete, there should be no difference. Someone else pipe up if you've got something to add that's intelligent, accurate, and to the point.

[@MarbledPaladin]

ElmoIsBold oops, you are right... I think I better explain my problem... My phone service entrance currently goes through a hole made in the door lintel (the top non-movable part of a door) and will have to be replaced eventually... I will need to drill a hole in my foundation instead just above the door (there is like 8-10 inches before the end of the foundation) and I was wondering if there is a rule a to how big a hole can be in that area... The house is about 50 years old and I don't want to weaken and maybe crack the concrete...

[@ElmoIsBold]

MarbledPaladin I hear you saying that you need to drill through your 8" foundation wall above where your door opening goes through it, and the height of the door only leaves 8-10" of concrete foundation wall above it. That's no problem for a 1/2" hole. Yes, it pounds hard, but it's not like swinging a 16lb hammer at it. If you hit rebar, try a bit higher or lower somewhere else.

[@joeskis]

Ok but what do I use to demolish my old cistern? I need to see how well chisel bits work.

[@tomkelly8827]

Thanks for showing that! I was wondering why the prices were so different and now I see why!

[@imaslowlerner]

we had a company out installing a new heat and air unit, a few weeks later I couldn't find my Hilti. Couldn't say for sure that my drill left with them. I miss my old Hilti, it gets the job done. 😂

[@shadowguidr7042]

imaslowlerner Slam a review up. They don't just go walkies.

[@mrbluenun]

Can you explain how the rotary hammer works please?

[@z-magnificent]

Anyone know if that style of dewalt hammer drill with a paddle mixer (DW511 in particular) would be sufficient for mixing up 5 gallon buckets of concrete with minimal aggregate? (and switched to normal drill mode)

[@kanishka.b8550]

This helped me to figure out whether my ne hammer drill is defective or not.. I’ve previously used rotary drills and recently I brought a hammer drill. The sound of it when drilling concrete is awful.. not a nice hammering sound like in rotary drill. Turns out it’s the normal sound of a hammer drill.😑

[@TickyTack23]

It sucks when you start drilling and hit rebar.

[@HealthIsPower]

Use a very strong magnet first to check!

[@ck8291]

HealthIsPower tks for the idea bro

[@rufie83]

or a water or gas conduit ;-)

[@josegomez6549]

Sky Pup what happens when you hit a post tension cable? I've never come across those

[@thatguywiththeface1741]

Jose Gomez it compromises it, gotta replace it.

[@roosterschleeter2323]

I recently got a dewalt roto.. And a corded makita.. And a cordless 18v makita. And a 36v makita.. And another makita corded and a cordless hilti.. To add to my hilti te56.. I've got a problem

[@bFORCe2003]

Rotary Hammer drills are the way to go but dang....that hammer drill is quality, the ones I've used take longer than that.

[@gtadiamondtools8713]

without any arguments, rotary hammer drill is the only way to go......

[@6lr6ak6]

The difference is night and day, and with Bosch Speedxtreme bits it'll drill through the rebar.

[@flavacreations]

Great video thanks for the heads up

[@skeletonsslayer8827]

hi. i really appreciate this video. more importantly what did you use to cut out that slab of concrete? we are looking to cut a similar opening but 18" thick.

[@AK-47ISTHEWAY]

He most likely used a diamond tipped concrete saw of some sort

[@boat6868]

That is a nice demonstration...thanks for the vid.

[@onzkicg]

lol 😂 just like he sliced a part in basement. Hey that’s dewalt looks good in hand, other one looks really huge. But which one can drill neat/ clean holes? I mean like the edges of hole isn’t cracked, but neat. I plan to get one to drill interior concrete wall to hang cabinets, basically few seasonal DIY. I’m only renting so I’m very particular in getting clean holes that I can easily repair when I leave. thanks

[@MustacheVerra]

That's impressive and thanks for that. But i was hoping to get an explanation as to what is the mechanical differences between them? Thanks.

[@joe4171]

MustacheVerra In a rotary hammer, a cylinder of air is compressed by a piston, which in turn beats the bit. In a hammer drill, two ribbed metal discs click in and out against one another, causing impact.

[@joe4171]

MustacheVerra rotary hammers definitely have less impact

[@MustacheVerra]

Got it. Thanks Joe.

[@wilfredoserrano4777]

My DeWalt Drill shorted how can I fixit