{"product_id":"3-8mm-sintered-diamond-core-drill-set-5pcs","title":"3-8mm Sintered Diamond Core Drill Bit Set, 5 Pcs – Durable \u0026 Efficient for Gemstone, Glass \u0026 Ceramic Cutting","description":"\u003ch3\u003eOverview — 5-Piece Professional Sintered Diamond Core Drill Set\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003e5-Piece Sintered Diamond Core Drill Set (3mm, 4mm, 5mm, 6mm, 8mm)\u003c\/strong\u003e is engineered for high-performance drilling and core extraction in ultra-hard materials including gemstone, agate, jade, glass, ceramics, porcelain tile, and granite. Unlike electroplated bits with only a surface layer of abrasive, these sintered diamond core drills feature a solid, metal-bonded matrix with diamonds embedded throughout the entire cutting wall, delivering up to \u003cstrong\u003e3 to 5 times longer tool life\u003c\/strong\u003e and continuous self-sharpening performance.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComplete 5-Size Assortment:\u003c\/strong\u003e Includes 3mm, 4mm, 5mm, 6mm, and 8mm outer diameter drills, covering essential micro-drilling, stringing hole, water passage, and mounting applications.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSolid Sintered Diamond Matrix:\u003c\/strong\u003e Heavy-duty metal bond holds diamond crystals uniformly throughout the segment wall, maintaining sharp cutting edges across hundreds of drilling cycles.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHollow Annulus Core Extraction:\u003c\/strong\u003e Thin-wall core geometry cuts only a narrow kerf around the circumference, drastically reducing cutting resistance, heat buildup, and edge chipping.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStraight Standard Shank:\u003c\/strong\u003e Precision concentric shank fits standard rotary tools, bench drill presses, water-swivel chucks, and CNC spindle attachments.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLapidary \u0026amp; Gemstone Working:\u003c\/strong\u003e Drilling precision pendant holes, bead channels, and core plugs in agate, quartz, jasper, sapphire, and jade.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGlass \u0026amp; Tile Cold Working:\u003c\/strong\u003e Clean entry and breakout in stained glass, fused glass bottles, ceramic tiles, and porcelain slabs without micro-fracturing.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStonework \u0026amp; Geological Sampling:\u003c\/strong\u003e Sampling and anchoring in granite, marble, and composite hard stones.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eOperating Guidelines\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAlways Use Water Cooling:\u003c\/strong\u003e Constant water feed or submersion is required to lubricate the cut, flush away slurry, and prevent diamond thermal degradation. Never run dry.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e45-Degree Initial Entry:\u003c\/strong\u003e Start the drill at a 45° angle to create a crescent groove on the material surface to eliminate bit skating, then slowly pivot the tool perpendicular (90°) once the channel is established.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGentle Pulsing Pressure:\u003c\/strong\u003e Apply light, steady pressure and periodically pulse the drill up and down to allow water to flush out accumulated rock and glass slurry.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"hanslapidarytool","offers":[{"title":"Default Title","offer_id":54283475222712,"sku":null,"price":37.61,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0570\/3217\/9896\/files\/Metal_Bonded_Core_Drill.jpg?v=1742868611","url":"https:\/\/lapidarygrinder.com\/en-ca\/products\/3-8mm-sintered-diamond-core-drill-set-5pcs","provider":"hanslapidarytool","version":"1.0","type":"link"}