A glass drill bit just like any other drilling bit is used for cutting purposes. However, the glass drill bit is used primarily in the cutting of glass. The bits are fitted into a drill which rotates at a very high speed resulting in the smooth boring of cylindrical holes of varying sizes in glass. The terms drill bit and drill usually cause confusion as they are sometimes used to describe both the cutter which is the drill bit and the holder of the cutter which is the drill. 

The glass drill bit is used together with the electric powered drill to drill holes through glass and other glasslike materials such as tiles and ceramics. A glass cutting drill bit usually has its tip coated with pieces of industrial diamond which help in the drilling process. The diamond pieces rub their way through the glass in an action that can only be described as similar to that of sandpaper. This minimizes the risk of breakages and cracks. The finesse of the rubbing action of a diamond drill bit for glass depends on its texture which might range from very fine to rough. This ensures that the diamond coating found in different glass drill bits matches to their intended task. 

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Difference Between A Glass Cutting Drill Bit And Other Drilling Bits

Metal and wood drill bits usually have their design based on the ever popular traditional twist architecture. The resulting flutes in metal and wood drill bits are used to bore into the material as well as in guiding waste material out of the hole. The diamond drill bit for glass on the other hand is straight, smooth—devoid of the flutes common in metal and wood drill bits and has a texture that can be aptly categorized as rough. When glass is being drilled, the ensuing waste material is a fine dust which does not need to be removed like is the case with wooden and metal shavings.

It is possible to sharpen drill bits for metal and wood once their cutting edges start being blunt. However, a glass drill bit is rendered useless once its diamond coating wears off. The longevity of the glass drill bit depends on several factors.

Factors Affecting Longevity Of Glass Drill Bit

  • The hardness of the surface being drilled

  • The thickness of the glass being drilled

  • Exerted pressure

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  • Type of lubrication and amount

  • Operator’s skills


The diamond coating of the drill bit for glass can last for years or it can last only for the duration it takes to drill a single hole. The drill should be continuously monitored so as to avoid sudden breakages and cracking which might be dangerous.

The glass cutting drill bit should be used in a well lubricated environment for optimum results. Lubrication of a glass drill bit can easily be done using water which is directed over to the drilling point. However, utmost care should be observed especially when working with electric drills. Should the drill get in contact with water, serious harm to both the machine and operator may arise. The glass drill bit should always be used with moderate to light pressure and should ideally be left to drill the glass at its own natural speed.