Multi-Material Drilling Accessories

Multi-material drill bits are designed to drill masonry, wood and metal with a single tool, which is useful when you often change substrate. For concrete and solid masonry, however, a dedicated bit with hammer action gives better results. Check on the label which materials the manufacturer states and choose the diameter according to the wall plug or screw to be inserted.

A 19- or 85-piece set covers many diameters and types of work, and suits those who drill occasionally or need several sizes. A single bit is better for a precise diameter that you use often, where durability matters. In sets, check which materials are covered and whether there are screwdriver bits.

Adaptors let you fit bits with a hexagonal or cylindrical shank to a hammer drill with an SDS fitting. The type of fitting on the machine must be checked first of all, because SDS-Plus and SDS-Max are not interchangeable without a dedicated adaptor. For example, there is an SDS-Max to SDS-Plus adaptor for using smaller accessories on machines with a larger fitting.

To centre a hole, use a centring bit or a jig, which guides the bit to the exact spot before drilling. On smooth surfaces, such as metal, first make a mark with a centre punch. When the same hole has to be repeated several times, the jig prevents slipping and off-axis holes.

Not always. Wood bits have a geometry designed for soft fibres and can overheat or wander on metal. For metal you need high-speed steel bits, such as the HSS ones found in mixed sets. Use a lubricant suited to metal and reduce the pressure to avoid breaking the bit.

Start at low speed and increase it only once the bit has entered the material. Switch on the hammer action on masonry only if the bit is suitable, otherwise it overheats. Do not apply excessive pressure: let the bit do the work and clear the dust from the hole while drilling.

Electricians, plumbers and installers use bits and sets to fit wall plugs and make openings through masonry. In the workshop they are used to drill sheet metal and metal sections. Joiners use wood bits and sets for precision holes. Anyone fitting shelves or windows will also find jigs and centring bits useful.