Sintered granite diamond core drilling bit HUAZUAN Sintered Diamond Diamond Drill BitDiamond Sintered Diamond Drill Bits are also know as Sintered Diamond Core Drill Bits or Sintered Diamond Hole Saws.  These are professional quality, heavy-duty diamond drill bits designed for use on ceramic tile, porcelain tile, limestone, sandstone, marble, granite, quartz and other stone, plus bricks, masonry, concrete block, and concrete.  Water must be used for lubrication.Sintered diamond drill bits are not very effective for glass type materials or softer stone materials such as slate and are not recommended for use on glass or slate.  Electroplated diamond bits are much more effective for those types of materials. Sintered diamond drill bits have the diamonds embedded into the metal of the drill bit tip rather than merely "boned" to the tip as with electroplated diamond drill bits.  As the tip wears down on a sintered diamond drill bit, new diamonds come to the surface.  The tip sidewall of HUAZUAN Sintered Diamond Drill Bits is 2mm thick on the smaller size bits (1" and below) and increases to 2.5mm to 3mm thick on larger size bits. Sintered diamond drill bits are heavy-duty bits designed for long life.  Generally, sintered bits will have a long life of 20 to 30 or more times the life of a electroplated diamond drill bit, if used properly.  The heavy-duty design provides long life when drilling in very hard materials such as porcelain tile, granite and hard stones.Diamond drill bits are easy to use, but there are many drilling techniques that are different from standard steel-bit drilling.  Diamond drill bit usage can also vary depending upon the diamond drill bit type and the specific manufacturer.Diamond Drill BitsRecommended Drill SpeedsDesigned for long-term use in materials up to 1-3/4" thick(Not for use with Hammer Drills)Sintered Diamond Drill Bitwith optional center pilot bit.Because diamond drill bits are used to drill in extremely hard materials, it is very important to use proper drill pres to keep from overheating the drill bit.  Excessive pres is merely converted to heat energy and can burn up a bit or cause heat fractures in the material being drilled.Sintered Diamond Drill BitsRecommended Drill Head Pressure*WARNING:Drill press arm gears leverage hand pres by a factor of about 6 to 8. So 2 lbs of hand pres on the drill press arm can apply up to 16 lbs of pres to the drillhead.Starting a Hole Saw / Core Drill andUsing A Center Pilot Starter BitStarting a core drill / hole saw style drill bit can sometimes be difficult. The Sintered Drill Bits over 1" in size are also designed to accept a Center Pilot Bit. The optional Pilot Bit is available below.If a Center Pilot Bit is used to start the drill bit, it is important to remove the pilot bit as soon as possible after the diamond drill bit has started drilling.  The carbide pilot bits cause the diamond bit to drill very slowly and the pilot bit can wear out quickly when drilling in very hard materials.1. Factory with more than 20 years experience in diamond tool industry.2. A great quantity of formula special for all kinds of different stone.3. Approved quality with factory price.4. Long lifespan, good sharpness, stable performance and high cutting efficiency.5. Custom-design can be meet upon request, and small trial order available any time.6. Different market need different quality and sizes. We can make all kinds of sizes and quality or price according your requirement.