Diamond Drill Bits
Diamond drill bits are used for specialised drilling tasks that other bits are not hard enough to tackle. While they are relatively niche, there are no substitutes for the tasks that they can perform.Purpose
Diamond is one of the hardest substances known to humankind, only beaten out by a few specialised lab-made materials. Its extreme hardness allows diamond drills to drill through materials that would defeat ordinary drill bits such as glass, porcelain and stone. They have a range of applications for construction and DIY use, as well as niche tasks in jewellery making and other crafts. However, diamond drill bits are a specialised tool that is totally unsuitable for some tasks. In particular, they should not be used to drill through soft woods or metals, as they will quickly choke up the bit.Construction
There are two major types of diamond drill bit. Electroplated drill bits use nickel to bond a single layer of diamond to the bit, while sintered drill bits feature multiple layers of diamond. Sintered bits are more costly but also last longer, as more diamond is exposed as outer layers are worn away. The other major construction issue for diamond drill bits is cooling. The bits can become very hot during use and drill bit makers and users have invented various strategies to prevent this. One strategy is to run water over the target material and the drill bit, although this should be done with care to avoid electrical issues. Other diamond drill bits are designed to not require water cooling. Often these are filled with wax that melts during use, acting as a heat sink, while some are simply made from high-strength materials. Typically, drill bit manufacturers recommend using diamond drill bits at low speeds.Compatibility
Diamond drill bits come in a variety of sizes. They can be used with ordinary power drills, although the smaller bits may require a chuck to fit the drill. However, diamond drill bits should only be used with standard rotary drills, not hammer drills.Other Specialised Drill Bits
Diamond drill bits are not the only specialised drill bit used for certain materials. High speed steel drill bits are favoured for drilling through metal, as they can be used at extremely high speeds. Tungsten carbide drill bits are also extremely hard and are suitable for drilling masonry. Brad point drill bits drill neat, accurate holes in wood and feature wide grooves that pull sawdust up and out of the hole.