Item Type: Hole Drill Bits Material: Emery + High Speed Steel Weight: Approx. 455g / 16oz Product Specifications: 8mm / 0.3in, 10mm / 0.4in, 12mm / 0.5in, 14mm / 0.6in, 16mm / 0.6in, 18mm / 0.7in, 20mm / 0.8in, 22mm / 0.9in, 25mm / 1.0in, 28mm / 1.1in, 30mm / 1.2in, 35mm / 1.4in, 40mm / 1.6in, 45mm / 1.8in, 50mm / 2.0in, +15pcs 6mm / 0.2in Scope of Application: Marble, glass openings, etc. 1CUTTING STRENGTH The opening is neat and smooth, without broken edges, not easy to shake and chip, small cutting resistance, stable drilling, provides excellent cutting strength. 2HIGH HARDNESS The use of high quality emery + high speed steel material can maximize the service life of the tool and has good corrosion resistance. 3MULTI PURPOSE: Multifunctional marble hole opener bit kit is widely used in granite and marble, masonry, concrete, ceramic tiles, glass, ceramics, stone, etc. 4HOLE OPENER KIT Includes 8/10/12/14/16/18/20/22/25/28/30/35/40/45/50mm+15pcs 6mm openers to meet various needs. 5SAFE OPERATION Easy installation, all marble drill bits are processed to achieve smooth and precise surface treatment to achieve good cutting strength.1. Please allow 0?1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.30 x Hole Drill Bits