avoid sparks, as well as special tube magnetic drilling machines that can be fixed on pipes of different sizes, even inside. Heavy-duty plate drilling machines provide high-quality solutions in the manufacturing of steel construction, bridge construction, shipyards, and various fields of the construction sector. Drilling in wood Wood being softer than most metals, drilling in wood is considerably easier and faster than drilling in metal. Cutting fluids are not used or needed. The main issue in drilling wood is ensuring clean entry and exit holes and preventing burning. Avoiding burning is a question of using sharp bits and the appropriate cutting speed. Drill bits can tear out chips of wood around the top and bottom of the hole and this is undesirable in fine woodworking applications. The ubiquitous twist drill bits used in metalworking also work well in wood, but they tend to chip wood out at the entry and exit of the hole. In some cases, as in holes for rough carpentry, the quality of the hole does not matter, and a number of bits for fast cutting in wood exist, including spade bits and self-feeding auger bits. Many types of specialised drill bits for boring clean holes in wood have been developed, including brad-point bits, Forstner bits and hole saws. Chipping on exit can be minimized by using a piece of wood as backing behind the work piece, and the same technique is sometimes used to keep the hole entry neat. Holes are easier to start in wood as the drill bit can be accurately positioned by pushing it into the wood and creating a dimple. The bit will thus have little tendency to wander. Others Some materials like plastics as well as other non-metals and some metals have a tendency to heat up enough to expand making the hole smaller than desired. Related processes The following are some related processes that often accompany drilling: Counterboring This process creates a stepped hole in which a larger diameter follows a smaller diameter partially into a hole. Countersinking This process is similar to counterboring but the step in the hole is cone-shaped. Boring Boring precisely enlarges an already existing hole using a single point cutter. Friction drilling drilling holes using plastic deformation of the subject (under heat and pressure) instead of cutting it. Reaming Reaming is designed to enlarge the size of a hole to leave smooth sides. Spot facing