Hammer drills are for drilling masonry and other hard materials by mixing rotation with rapid blows; switch off hammer mode for wood or metal.
If a regular drill stalls in brick or concrete, a hammer drill steps in. It spins like any drill, and at the same time it pulses the bit forward along its axis. The tiny strikes grind brittle material while the flutes clear dust, so the hole grows without burning the bit.
Pick it up for anchors in brick, block, and poured concrete, light work in stone, and quick pilot holes through mortar. Turn the hammer off for steel or timber and you get a normal drill driver again.
Common Jobs And The Right Setup
| Task Or Material | Mode And Tool | Bit Or Accessory And Tips |
|---|---|---|
| Tapcon or screw anchor in cured concrete | Hammer drill, hammer mode on; set low to mid speed | Carbide masonry bit; clear dust often; use depth stop |
| Plastic wall plug in brick | Hammer drill on; moderate speed | Masonry bit matching plug; brush out hole |
| Through-hole in cinder block (web) | Hammer drill on; start slow then increase | Carbide bit; support both sides to reduce blow-out |
| Pilot hole in mortar for clip | Hammer drill on; gentle pressure | Small masonry bit; widen after test fit |
| Tile over backer board | Rotation only (no hammer) | Glass/tile bit; tape the glaze; keep the bit cool |
| Timber behind masonry veneer | Start a masonry pilot, then switch to wood bit | Hammer on for veneer, off for wood; spade or auger for the stud |
| Light work in natural stone | Hammer drill on; slow, steady feed | Quality masonry bit; keep the bit straight |
| Metal lintel behind brick | Rotation only; high torque | HSS or cobalt bit; oil for cooling |
| Small hole in poured slab for sensor lead | Hammer drill on; short pecks | Carbide bit; vacuum dust as you drill |
| Brittle block near an edge | Hammer drill on; slow speed, low force | Sharp bit; stop short of edges to avoid cracks |
How A Hammer Drill Works
Inside the nose of the tool, two ridged discs ride against each other. When you select hammer mode, the discs slip over the ridges and create a rapid in-line thump while the chuck turns. That impact rate is listed as blows per minute. More blows help the bit chip masonry, yet the cut still needs rotation to stay round.
This mechanism is different from a rotary hammer, which drives the bit with a piston and uses SDS shanks. A rotary hammer hits much harder and accepts chisels; a hammer drill stays lighter and uses a standard three-jaw chuck.
What Are Hammer Drills Used For In Practice
Most people reach for one to set anchors and plugs. Drilling a dozen 6 mm to 10 mm holes in brick or cured concrete for fixtures is where this tool shines. It also handles small holes in block, pavers, and many stones, provided you let the bit do the work.
For bigger diameters, deep holes, or heavy rebar risk, a rotary hammer is the better pick. It delivers stronger blows with less effort and holds SDS bits that resist slip under load.
Hammer Drill Vs Rotary Hammer Vs Impact Driver
A hammer drill combines spin and light forward hits for masonry drilling. A rotary hammer focuses on hammer energy and uses SDS bits; it also chisels when set to hammer-only. An impact driver pulses torque around the axis for driving screws and bolts; it does not chip concrete.
Use a hammer drill for general holes up to medium size in common masonry. Use a rotary hammer for anchors in hard concrete, deep holes, core bits, or any chiseling. Use an impact driver when you need fast screw driving or lag bolts.
Bits, Shanks, And Speed
Masonry Bits
Standard masonry bits have a carbide tip brazed to a steel body. The cutting edges fracture the surface while the flutes carry dust out of the hole. Run too fast and heat dulls the tip; too slow and the bit rubs rather than cuts.
SDS Shanks
Hammer drills grip round or hex shanks in a three-jaw chuck. Rotary hammers use SDS shanks that lock into grooves so the bit slides freely under impact. If your work is mainly anchors in hard concrete, SDS speed and life can pay off.
Setups For Fast, Clean, Round Holes
Mark the spot, then confirm the wall build-up with a detector or a small pilot. If you hit rebar, move the hole or switch to the right cutter after approval. Use the depth rod so fasteners seat at the proper embedment.
Start straight with light pressure. Work in short pecks, withdraw to clear dust, and keep the flutes clear. Where you can, capture debris with a shroud and a vacuum rated for fine dust.
For fixtures on tile, begin with rotation only and a tile bit, then change to a masonry bit once you reach the backer. A strip of tape over glossy glaze keeps the bit from skating. For hollow block, support both faces and slow down as you break through.
Pick The Right Tool For The Job
| Task | Best Tool | Reason |
|---|---|---|
| Anchor holes in hard structural concrete | Rotary hammer (SDS-Plus or SDS-Max) | Higher impact energy with less effort |
| Dozens of small holes in brick or block | Hammer drill | Good speed, easy to handle |
| Chiseling a channel for conduit | Rotary hammer | Hammer-only mode with chisel bits |
| Driving long screws or lags | Impact driver | High torque pulses without stripping |
| Drilling metal or wood | Drill/driver or hammer drill with hammer off | Clean holes and better control |
| Pilot hole through mortar | Hammer drill | Quick, neat hole with light blows |
Corded Or Cordless, And Handy Features
Cordless hammer drills with brushless motors deliver strong runtime and plenty of torque for common masonry. Corded models keep steady power on long days and avoid battery swaps. Pick variable speed, a side handle, a depth stop, and a clutch for safer starts.
Look at blow rate as well as no-load speed. A second gear helps match bit size. A detachable dust shroud and a HEPA-capable vacuum port keep the workspace cleaner.
Safety, Dust, And Personal Protection
Masonry drilling creates fine crystalline silica dust per OSHA silica guidance. Use a tight-fitting respirator when needed, pair the tool with a dust shroud, and connect a vacuum with a high-efficiency filter. Eye and ear protection, gloves with grip, and stable footing matter too.
Secure workpieces, keep the side handle fitted, and let the clutch save your wrist if the bit binds. Unplug or remove the battery before changing bits. Store sharp bits where tips stay covered.
Buying Tips That Save Time
Match the tool to your most common hole size. If most jobs are under 10 mm in brick or block, a compact hammer drill is perfect. If your day is anchors in hard concrete, step up to an SDS rotary hammer instead.
Buy fresh masonry bits and retire blue, chipped tips. Carry sizes that match common anchors and wall plugs. Add a tile bit, a set of HSS bits for metal, and a countersink for clean wood holes behind hardware.
Care And Maintenance
Blow dust from the chuck and vents after each session. Wipe the tool, check the cord or battery contacts, and inspect the side handle. A light drop of oil on a plain chuck helps it tighten smoothly.
Store bits in sleeves, not loose in a bag. Sharpen or replace dull masonry bits; badly worn tips slow the job and heat the drill. Keep the depth rod with the tool so embedment stays consistent on every hole.
Quick Troubleshooting
If holes wander, check for a bent bit or worn chuck jaws. If progress slows, lower speed, add gentle pressure, and clear dust more often. Ringing ears and numb fingers hint that you need hearing protection.
Hammer Drill Settings And Technique
On dense concrete, work in short bursts and let the motor rest between holes. Heat shortens bit life and can glaze the hole. Pauses also give the vacuum time to catch up so the hole stays to size.
Common Mistakes To Avoid
Leaving hammer mode on for steel or timber. That pounding makes ragged holes and can chip a carbide tip designed for masonry. Use plain rotation with the right bit instead.
Running at full speed with a dull bit. High rpm with a rounded edge only polishes the surface and builds heat. Fresh edges cut faster and keep the hole round.
Skipping dust removal. Packed dust drags on the flutes and swells inside the hole, which can stop an anchor from reaching the mark. Brush or vacuum during and after drilling.
Mixing up diameters. Anchors have specific drill sizes and embedment depths; match the label and use the depth stop so hardware seats correctly.
Project Planning And Hole Layout
Use a template or a level to set hole spacing before you drill. A quick pilot marks the center without wandering, and blue tape gives you a place to write each anchor size next to the mark. On finished walls, a dust shroud keeps the surface cleaner so layout lines stay visible.
Think about what sits behind the surface. Lintels, reinforcement, and services can block a straight path. A detector lowers the chance of striking metal, and a small pilot gives you time to adjust the location if needed.
Check the user manual for the correct accessory range and clean the vents to keep cooling air moving. Keep spare carbon brushes or a charged battery ready so the tool stays in service when a job runs long.