Rotary Hammer

[dsan]

Hi Folks,

This is my first posting here and I was hoping to get some feedback. I just bought a 20lb Rotary hammer with a spline drive and was told that I could use this tool with a clay spade. I am concerned because I already have rotary hammer to drill holes only but this 20 lb hammer has a hammer only mechanism and a drilling with hammer mode. Will this hammer be able to use a clay spade as this is what I bought it for? Any suggestions will be appreciated.

[Bob D.]

I would suggest you give us the make and model, then someone can give you an educated answer and not a guess.

[dsan]

Fair enough. I wasn't sure if I would be kicked out of this forum for naming another tool manufacter. It is a Makita HR 3851.

[jbergstrom]

dsan welcome to the forum :)

If you look here (http://www.makita.com/menu.php?pg=accessory_list&tag=acc_concrete_rot_demo&cat_tag=120&f=HR3851) you'll see the clay spade attachment for your HR3851 (http://www.makita.com/menu.php?pg=product_det&tag=HR3851) I just want to make a minor correction, your rotary hammer weighs 16.5 lbs. not 20 lbs. as someone may have told you.

Because I dig holes in the ground for a big part of my living (fences, decks, gazebos etc.) I have researched just about everything there is to know about demolition hammers and rotary hammers in the specific application of digging dirt with a clay spade attachment or bit.

IMHO the tool you bought specifically for digging dirt, that is using a clay spade, is marginal at best. Technically yes the tool will take a clay spade and will most likely dig through dirt etc. but how well will it accomplish this task is the question?

At the risk of boring you I'll tell you how I first came across a demolition hammer being used with a clay spade... A buddy of mine installs irrigation systems for a living and as he was short of help once upon a time I gave him a hand on one of his projects. The ground we were trenching was pretty ugly stuff, full of shale etc. He said just a minute I'll be right back... he ran home (near our jobsite) and returned with his Hilti TE 905 (http://www.hilti.ca/holca/modules/prcat/prca_navigation.jsp?OID=-27752) along with a clay spade bit for it. Well it was like night and day, we went from about 10' of trench an hour to about 30'. I gave him a hard time and suggested we use "jack" all the time (I don't know what he was saving it for?)
This is what got me thinking and I started researching for my own solution to digging holes for fence posts, footings etc. etc. While I liked the Hilti I wasn't prepared at the time to spend over two thousand bucks on one :eek:
I also found it a little on the light side for what I needed. It was perfect for him because his trenches were only 6" - 8" deep.
I looked at the Dewalt D25940K (http://www.dewalt.com/us/products/tool_detail.asp?productID=5631) with it's 3/4" hex bits and it's twin the D25900K (http://www.dewalt.com/us/products/tool_detail.asp?productID=3056) with SDS Max bits. These two demolition hammers seemed good, they weighed in at about 20 lbs. and had some nice features. They were also quite a bit cheaper than the Hilti so they went on the top of my list. However the search continued... Another friend of mine manages a tool store and he kept telling me that I should come and check out the Hitachi demo hammers he had in stock. He had the Dewalts, some Makitas and the big bruiser from Bosch as well. He knew what I was going to be using it for and insisted that the Hitachi H65SC (http://www.hitachipowertools.ca/en/Products?cat=5&pid=218) was the one for me. After scoping it out I had to agree :D
I paid around $800.00 cdn for it (he threw in three extra bits and an 80' cord for another $100.00) The bits are 1 3/16" hex so breaking one is almost next to impossible in my applications. It weighs in at about 33 lbs. (closer to 40 lbs. with the bit) and this is important because the weight of the tool does all the work. I don't get as tired running my Hitachi as I did running my buddies Hilti TE 905.

Long story short I'm just telling you this because you said the "main" reason you got the Makita HR3851 (http://www.makita.com/menu.php?pg=product_det&tag=HR3851) was to use the clay spade with it to dig dirt. You said you already have a rotary hammer and wouldn't really need the rotary function of this unit. I'm telling you that you would probably be better off with a true "demolition hammer" (your Makita is only one step away from being such) which would make digging with a clay spade easier. Just the ergonomics of the true demo hammers alone make them easier to handle and maneuver etc. You may not need one as heavy as mine but like i said more weight equals less fatigue.

Makita HR3851
2020

Dewalt D25940K
2017

Hilti TE 905
2018

Hitachi H65SC
2019

Makita HM1304B
2021


I hope this helps :cool:

[dsan]

Thanks. BTW you rock.:D

[markts30]

For demo and digging we use the Bosch "brute"...
We have the chisel bits as well as the clay spade and even a compacting plate for it...
Saves a lot of picking and makes digging in packed dirt and rock so much easier...
http://66.77.255.87/Images/BOSCHTOOLS/11304_B/WEB_PD/11304_B_pd.jpg

[dsan]

Isn't the brute a little too heavy?

[jbergstrom]

Isn't the brute a little too heavy?

dsan I guess it depends on what you have to dig ;)

The Bosch Brute (http://www.boschtools.com/tools/tools-detail.htm?H=175982&G=54916&I=55043) weighs in at 64 lbs. With the bit you're looking at around 70 lbs.:eek::D:cool:

I guess as long as you eat your Wheatie's or want to build some muscle...

I once spent 45 days on a 90 lb. jack hammer (air powered) in the bottom of the digester building in a pulp and paper mill busting out old footings of calcified cement with rebar running about every 6" or so...
I sssttarrtted ttttooo sssseeeee ttthhee wwwwoorrlllddd aa lliiittttllle differently. I was vibrating in my sleep :eek::D:p

Seriously though the Brute is a good piece of equipment, it's great at busting through asphalt, concrete etc. etc. I would think that in real ugly ground and faced with digging large footings etc. (3' x3') on a construction site the Bosch with a clay spade would help make short work out of anything you threw at it.

However in my application the 40 lb. Hitachi is just right. I can spend all day digging holes through any type of ground with very little fatigue. Most of my post holes or footings are generally about 1' in diameter and 2' - 3' deep. I also use it to break apart rotten post stubs that were placed in concrete and busting through asphalt etc. Other tools I use for digging include a couple of long bars (one with a wide chisel end for cutting through roots), various shovels and a clam shell post hole digger for removing the loose soil from the hole.

Nearing 2'
2022

Here is a mid range Bosch demo hammer (http://www.boschtools.com/tools/tools-detail.htm?H=175982&G=54916&I=80519) that is in the same weight class as the one i use (39 lbs.)

Cheers :)