30mm Drill Bits

When you need to bore large clearance holes for major installations, our professional range of 30mm drill bits delivers the power and precision required. Built for heavy-duty applications, these large-diameter bits are engineered to handle extreme torque and resist wear, allowing you to drive through tough structural materials efficiently. Whether you are sinking large anchor bolts, running thick plumbing pipes or commercial cables through walls and joists, or enlarging existing holes in metalwork, a dedicated 30mm bit is an essential addition to your heavy-duty toolkit.

We stock a selection of 30mm profiles designed for specific tasks. For heavy masonry and concrete, choose our highly durable SDS max hammer bits, designed to minimise vibration and maximise energy transfer from large rotary hammers. For fast, clean drilling in timber, our 30mm range includes deep-boring auger bits and flat wood bits. If you need to drill through sheet metal or plastics, our versatile step drill bits offer a smooth, progressive cut up to 30mm. Rely on trade-quality performance from leading brands like Bosch, Draper, and Toolpak.

Frequently Asked Questions | FAQs

Can I use a 30mm drill bit in a standard combi drill?

Generally, no. A 30mm hole requires significant torque and power, which is usually beyond the capacity of a standard 18V combi drill. Attempting to drill a 30mm hole in dense wood or masonry with a standard drill will likely stall the motor, drain the battery quickly, or even damage the tool. Furthermore, most 30mm bits feature SDS Max or large hex shanks that will not fit a standard 13mm chuck. For a hole this size, you should use a heavy-duty rotary hammer drill (for masonry) or a high-torque, low-speed drill (for wood).

What is a 30mm step drill bit used for?

A step drill bit (or cone bit) ending at 30mm is used primarily for drilling into thin materials like sheet metal, plastics, and laminates. The stepped design allows you to drill a hole starting from a small diameter (e.g., 4mm) and gradually enlarge it step-by-step up to 30mm using a single bit. This is ideal for creating clean, burr-free holes for electrical glands or pipework in trunking or control panels.

What is the difference between an SDS Plus and SDS Max 30mm bit?

While both are used in rotary hammer drills, they have different shank designs and are not interchangeable. SDS Plus has a thinner shank (10mm) and is used for lighter-to-medium masonry drilling. SDS Max has a thicker, more robust shank (18mm) designed specifically for heavy-duty, high-impact rotary hammers. Because 30mm is a very large diameter for masonry, you will predominantly find 30mm bits in the SDS Max format, as it provides the necessary strength to handle the extreme torque required.