Drill Bit Stopped Drilling
- Material buildup:
- 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.
Hammer Drill
- Uses a rapid clutching action to produce a hammering effect on the turn of the hammer drill bit
- Sufficient for drilling holes up to about 1 inch in diameter
- Uses either a keyed or a keyless three-jaw chuck, similar to any standard drill
Rotary Hammer Drill
- Uses an actual hammering action within the drill to deliver a more powerful blow
- Sufficient for consistent use in drilling larger holes, up to a 2-inch diameter
- Rather than a chuck, rotary hammers use specific slotted drives
- Some include a “stop rotation” feature which allows for the tool to be used like a jackhammer, making it a popular tool for demolition projects
Due to the greater force of the rotary hammer, the differences extend to onboard components as well as the bits they use.
Rotary Hammer Drive Types
The three most common rotary hammer drives are:
- SDS/SDS+: also referred to as “SDS plus,” the meaning of the letters is often disputed in the trades but it is generally accepted that SDS stands for “slotted drive system.” SDS and SDS+ are the smallest of the rotary hammers and are limited to about a 1⅛-inch solid bit diameter capacity. The shanks of these bits and accessories have single drive slots on opposing sides.
- SDS-Max: the bigger sibling of the SDS+, SDS-Max can have a solid bit capacity of up to 2 inches on some rotary hammers. Shanks for SDS-Max bits and accessories are characterized by two drive slots on one side, and a single slot on the opposite side. Some of these include a stop-rotation feature.
- Spline: like the SDS-Max, this drive style can accommodate a bit capacity of up to 2 inches. Spline shanks on bits and accessories are characterized by evenly spaced teeth around their entire circumference, similar in look to a gear. Some of these include a stop-rotation feature.
All three drive types are industry standards, so they are interchangeable among brands and within the same drive.