Is there anything special about drills for hammer drills?
I have a bunch of carbide drills I got at garage sales over the years, and
while I don't mind wearing them out, I would like to use the ones best
suited for the task.
I just want to drill some shallow holes in a conglomerate rock that I think
is probably pretty hard.
Actually what he needs are percussive bits made for hammer drills.
A simple masonry bit will be destroyed within the first 20
revolutions on a hard material. Percussive bits or hammer drill
bits are the ONLY thing that will not be destroyed in a hammer
I just had to drill qty. 20 size 1/4" and 5/16" holes in a fieldstone
hearth to install a screen. You've correctly identified your need for
a hammer drill, and other posters have also correctly identified the
need for special bits. Lowe's and Home Depot sell them (make sure
they're marked as for a hammer drill), but I wasn't pleased with their
I recommend doing what I did - ditch the big boxes and go to your
local contractor's fastener supply house - look in the Yellow Pages
under "Fasteners - Industrial and Construction". I bought Simpson
bits and anchors and was pleased
(http://www.simpsonanchors.com/catalog/carbide/straight.html ). Also,
the sleeve, wedge, and epoxy anchors I looked at were priced at about
25% of what they charge at Lowes'/Home Depot, so that's a big savings
depending on how many you need. You can also get advice on your
specific needs. (I ended up with sleeve anchors.) At places like
this, paying cash helps the process, since they're usually set up for
contractors and don't like to mess around with credit cards or checks
from random homeowners.
So, with the Simpson bits, it took up to 45 seconds or so to drill 2"
deep in stone, but less than 10 seconds to drill the same depth in the
mortar between the stones. Also, one bit was good for about four to
six holes (assuming a mix of drilling into stone or mortar). The bits
were priced at about $3.50 each, which was comparable to the prices at
Lowe's and Home Depot, but as I said, in my experience these bits did
much better for the same price.
FYI, Simpson is one big fastener company - the other is Hilti. Hilti
makes really good stuff, but it's expensive and some of the tools are
proprietary. Simpson is a little more user friendly.
Misc. thoughts: earplugs and glasses are a must. Shopvac out the dust
in the hole before installing anchor. The bits get super hot so be
careful when changing. Just for kicks, I tried a straight carbide bit
- it never penetrated the surface more than 1/8".
Anyway, as always, your mileage may vary. I have no connection to
either company except having used their products. Good luck.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.