18mm Drill Bits

Tackle heavy-duty construction, deep bore installations, and large clearance holes with our reliable range of 18mm drill bits. Built to endure high torque and prolonged use, these robust bits are designed to drive through tough materials quickly while maintaining precision. Whether you are sinking large masonry anchors, routing pipework and thick cables through timber joists, or fabricating metal, having the exact 18mm bit in your kit ensures clean results and prevents frustrating on-site delays.

Choose from a comprehensive selection of profiles tailored to your specific application. Our range includes heavy-duty SDS plus and SDS max hammer bits for powering through dense concrete, alongside extreme tri-flute and flat wood bits for rapid timber clearance. We also supply reduced-shank HSS blacksmith bits for metalwork and specialised dry diamond hole saws for hard ceramic tiles. Stock up on dependable, trade-quality accessories from industry-leading brands like Bosch, DeWalt, Toolpak, and Mexco.

Frequently Asked Questions | FAQs

What is an 18mm SDS Max drill bit used for?

SDS Max drill bits feature a thicker, more robust shank than standard SDS Plus bits, allowing them to handle the extreme power of heavy-duty rotary hammers. An 18mm SDS Max bit is ideal for drilling deep, wide holes into tough concrete, reinforced masonry, and blockwork for large structural anchors and heavy fixings.

What is the best 18mm drill bit for drilling into timber joists?

For routing cables and small pipes through timber joists, an 18mm flat wood bit (spade bit) or a tri-flute wood drill bit is the best choice. These bits are engineered for rapid cutting and fast waste removal, leaving a clean 18mm clearance hole with minimal effort and splintering.

How can I fit an 18mm metal drill bit into a standard drill chuck?

Most standard power drill chucks have a maximum capacity of 10mm or 13mm. To drill an 18mm hole in metal without upgrading your power tool, you should look for an 18mm reduced-shank HSS drill bit (sometimes called a blacksmith drill bit). These feature a stepped-down base that fits perfectly into standard chucks.