38mm Drill Bits

When you need to bore very large clearance holes for major installations, our professional range of 38mm drill bits provides the uncompromising power and precision you need. Designed for heavy-duty applications, these large-diameter bits are built to withstand extreme torque and friction, ensuring you can drive through thick, tough structural materials efficiently. Whether you are running waste pipes, routing heavy electrical trunking, or installing large, concealed cabinet hardware, a dedicated 38mm bit is essential for accurate, hassle-free work.

We supply a selection of 38mm profiles tailored to specific tasks and power tools. For exceptionally fast and clean clearance in timber, our 38mm range includes flat wood (spade) bits and precision Forstner bits, which are ideal for clean, flat-bottomed holes in joinery. If you need to drill clean, chip-free holes in tough ceramics, porcelain, or masonry, we offer specialised dry diamond core drill bits and tile hole saws. Ensure trade-quality performance with stock from trusted brands like Bosch, Mexco, Toolpak, and DeWalt.

Frequently Asked Questions | FAQs

What is a 38mm diamond core drill bit used for?

A 38mm diamond core drill bit is specifically designed to cut large, precise holes through tough masonry materials—such as brick, blockwork, and concrete—as well as hard ceramic or porcelain tiles. Rather than carving out the entire hole, a core bit cuts only the outer perimeter, removing a solid "core" of material. This makes the drilling process much faster and cleaner, which is ideal for routing pipes or vents through structural walls.

Can I use a 38mm flat wood bit in a standard combi drill?

Most standard 18V combi drills have a 13mm chuck, which is usually compatible with the 1/4" hex shank found on most flat wood bits. However, a 38mm hole requires a significant amount of torque. While you can physically fit the bit into the drill, boring a hole this large in dense timber will likely strain a standard combi drill, draining the battery quickly and potentially causing the motor to stall or overheat. It is recommended to use a high-torque, low-speed drill or a dedicated heavy-duty drill for holes of this size.

What is a 38mm Forstner bit used for?

A 38mm Forstner bit is primarily used in carpentry and furniture making. It is designed to bore very clean, precise, flat-bottomed holes in wood, MDF, and chipboard without tearing the grain. This specific size is often required for installing large, heavy-duty concealed hinges (such as those used on thick or oversized cabinet doors) or for recessing large hardware components.