Description 10pcs 7mm Diamond Hole Saw Drill Bits for Glass Ceramic MarbleSpecification Material Nickel PlatedHole Saw Diameters 7mm 0 28 inchLength 5cm 1 78 inchQuantity 10pcsFeatures Good performance and long life Excellent for making clean and accurate hole on glass and tile These diamond bits are capable of drilling into extremely hard materials such as stone and glass Use a low speed setting and Pproper cooling such as water to ensure longer lasting life Works better with a electric drill Excluding in the item Superior Performance Cut Holes in Marble Slate Glass Tile Stone etc How to use 1 Clamped firmly to a bench to allow for slow controlled drilling 2 If drilling in situ or at an awkward angle cna try following method 3 Make a template from a piece of timber or waste material locate this over the area where you want to drill your hole and use it as a guide to start the hole 4 Once youve got into the surface by 1mm to 2mm you can remove the guide and continue to drill in a controlled manner 5 Start your hole diagonally make a round trace and then hold drill straight Package Included 10 x Diamond Hole Saw More Details