Troubleshooting Common Hammer Drill Problems

When using a hammer drill to drill through hard brittle substances such as concrete or tile, there are a number of problems that can crop up that can cause your work to slow down or even stop. Below are a few common problems that can occur while using a hammer drill, also known as a rotary hammer, while drilling through various substances.

Work Piece Cracking

One of the biggest problems that people have when drilling through hard or brittle substances or surfaces is that the material being drilled will crack or shatter. This is caused when too much force is applied against the material being drilled. To prevent this, use gradually increasing amounts of pressure. Stop increasing the pressure when the amount of material being carried out of the hole by the flutes of the drill reaches a maximum amount.

Drill Bit Stops Drilling

The next biggest problem that you may face when drilling through concrete or tile is where the drill bit stops drilling into the material. This is caused by two things occurring. The first problem is that the flutes of the bit aren’t carrying enough material out of the hole. The other cause of a bound or jammed drill bit is caused when the bit comes into contact with a piece of rock. The solutions for these problems are below:

  • Material buildup: This problem can be cured by slowly moving the bit up and down in the hole every 30 seconds or so while drilling. Another trick is to keep a small length of tubing or a straw handy and cautiously blowing the dust out of the hole.
  • Bit jamming: When your drill bit contacts a piece of rock it can’t break, you need to help it. Insert a pointed rock punch or concrete nail in the hole and strike it sharply with a hammer a couple of times to break the rock. If your first attempt isn’t successful at breaking the rock, use more force with the hammer.


Spawling is where chips of the material being drilled break and fly off the material while it is being worked. This can be dangerous because these pieces are often quite sharp and can cause bodily injury. To minimize spawling, you first need to decrease the amount of pressure that you’re using on the drill. Rotary hammer manufacturers provide a rubber cup that fits over the end of the chuck and minimize the amount of material that is able to break off and fly away. This rubber cup is called a spawl shield.

Bit Jams

When a drill bit comes into glancing contact with a material it is unable to cut, it may bind up in the hole and you may not be able to remove it. When this happens, unplug the rotary hammer and remove the bit from the drill. Using a special type of wrench called a Stillson wrench, turn the drill bit counter clockwise to remove it from the hole. Once the bit is removed, the blockage should be cleared with a pointed masonry punch or a concrete nail.