Choosing the Correct Drill Bit for the Material
The material should always lead the choice of drill bit.
For concrete, brick and blockwork, use a masonry drill bit or SDS+ drill bit suitable for the substrate. SDS+ shanks are designed for compatible SDS+ machines and are widely used for site drilling into concrete and masonry.
For timber, use a wood drill bit that gives the hole type required. A clean pilot hole can help reduce splitting, keep the screw straight and make installation more controlled.
For metal, use a suitable metal drill bit such as HSS or cobalt, depending on the metal grade and drilling conditions. Slower speeds, steady pressure and suitable lubrication are often important when drilling harder metals to avoid overheating the bit.
For mixed materials, multi-purpose drill bits can be useful, especially where the exact material changes across the job. For high volume or demanding work, a material-specific drill bit will usually give better control and consistency.
Matching Drill Bits to Fixings and Fasteners
Correct hole preparation is essential for fixing performance. Many fixings rely on a drilled hole being the correct diameter, depth and condition.
A hole that is too small can make installation difficult and may damage the fixing. A hole that is too large can reduce grip, pull-out resistance or thread engagement. Dust left in the hole can also affect the way anchors, plugs, masonry screws and concrete screws install. For some concrete screw applications, guidance commonly recommends drilling deeper than the embedment depth and removing dust before installation.
When choosing a drill bit, check:
- The fixing diameter
- The recommended drill hole diameter
- The required drilling depth
- The substrate, such as concrete, brick, block, timber or metal
- The required clearance hole or pilot hole
- The shank type needed for the drill being used
- Whether the hole needs cleaning before the fixing is installed
Masonry screws are one common example where the pilot hole is critical, but the same principle applies across many fixing systems. Anchors, plugs, frame fixings, bolts, screws and rivets all depend on the hole being drilled correctly for the application.
SDS+ Drill Bits and Masonry Drilling
SDS+ drills are a common choice for drilling into concrete, brick, block and masonry on site. The SDS+ shank provides a secure fit in compatible machines and is suited to hammer drilling applications where standard straight shank bits may not be appropriate.
SDS+ masonry drill bits are commonly used for:
- Concrete drilling
- Brick and blockwork drilling
- Anchor hole preparation
- Frame fixing installation
- Masonry screw pilot holes
- Through-fixing work
- General construction drilling
When using SDS+ drill bits, make sure the drill, bit diameter and bit length are suitable for the fixing and the depth required. Longer drill bits are useful for deeper holes or through-fixing work, but the hole still needs to be drilled straight and to the correct diameter.
Top Drilling Tips
Before drilling, mark out the fixing positions clearly and check the substrate is suitable for the load and fixing type.
Drill square to the surface where possible. Angled holes can affect how the fixing seats and may reduce the quality of the installation.
Do not force a blunt or unsuitable drill bit. It can wander, overheat, oversize the hole or damage the surrounding material.
For masonry and concrete drilling, remove dust from the hole where the fixing system requires it. Hole cleaning is especially important for many anchors and concrete fixing applications.
For timber, pilot holes can reduce splitting and help fasteners drive straight. This is particularly useful close to edges, in hardwoods or when using larger diameter screws.
For metal, use suitable speed and pressure. Harder metals often need more care, and cobalt drill bits may be a better choice for stainless steel and tougher materials.
