If you have an SDS rotary hammer drill and you are looking to drill core holes in masonry, check out the Bosch Speed Core System.  The Bosch Speed core is a two piece system.  First choose the core size you would like to drill.  The cores are available in sizes starting at 1″ and go as large as 4-3/8″.  The cores have a thinner wall than what you would find on a larger SDS MAX core bit.  This creates less resistance and helps the smaller hammer power them.  You will also need to purchas a shank.  The shank has a built in starter bit and you simply screw the core onto the shank.  You can actually unscrew the core and add a different size core.  So in theory, you could have several different core sizes with just the one shank.

A couple of simple things to keep in mind when you are using an SDS core bit.  SDS Rotary hammers have a clutch to protect the user from injury.  If the bit were to bind up in the concrete, the tool will clutch out rather than throw the user off a ladder or injur them.  So if you are using larger size cores, be sure to work slow and let the tool do the work.  It’s a good idea to use an anti seize compound on the threads as after a while, it can be really hard to get the core back off the shank.  Some contractors will use a piece of copper cable wrapped around the shank between the core and where it contacts the shank to make it easier to remove.

What are a few of the applications for using a core bit on your SDS rotary hammer?  The obvious use would be running pipe through a wall and that is one reason we sell a good amount of the 2-9/16″ size that works well for installing 2″ EMT.  Another common use is for drilling holes in slabs for setting railing in concrete.  Certainly there are many more applications.  If you have ever had to drill a bunch of small holes in a wall and then punch out the concrete, you can see how valuable a product