Twist drill bit set: ⭐Package quantity: 2x 6mm(1/4"), 1x 8mm(5/16"), 1x 10mm(3/8"), 1x12mm(1/2") ⭐Material: High quality tungsten carbide tip ⭐Shank: 3-flats shank ⭐Color: Black & Silver ⭐Used for: tile, concrete, brick, glass, plastic and wood, etc. ⭐Feature: High quality, durable, pricise drilling in various materials at same time,convinient for use with long life time. ⭐User Instruction: Tool-Power drill. Do not use impact mode of drill or hammers. When drilling hard material (glass, porcelain floor tile, marble or granite), please use water for lubrication. 10pcs Diamond Coated Hole Saw Drill Bits: ⭐Package quantity: 6mm(1/4"), 8mm(5/16"), 10mm(3/8"), 14mm(9/16"), 16mm(5/8"), 18mm(11/16"), 22mm(7/8"), 35mm(1-1/6"), 40mm(1-1/2"), 50mm(2") ⭐Features: - This diamond bit core drilling removes a complete circle glass, tiles, marble, granite, ceramic or other material and only needs water for lubrication - Can be used with a standard electric drill (not included) - Easy to use, high quality, good performance, long life - Excellent for making clean and accurate hole on glass, tile and marble - Always use lubricant (water), otherwise the diamond core drill will burn - Start the hole diagonally, make a round trace and then hold drill drittoSpecifica ⭐If you smell burning, back off! Either your speed is too high or the pressure you're applying is too much. You're drill bit should never be hot to the touch, not even warm. - Slowest speed - Coolant - Minimum pressure The general rule is the smaller the diameter of your drill bit, the faster drill speed you can use. The harder your material, the slower drill speed you should use.
