{"product_id":"proxxon-diamond-drilling-grinding-bit-3-2mm-ball-2-pack-no-28234","title":"Proxxon Diamond Drilling \u0026 Grinding Bit — 3.2mm Ball (2-Pack)","description":"\u003ch2\u003eProxxon Diamond Drilling \u0026amp; Grinding Bit 3.2mm Ball (No. 28234) — Shape and Hollow Hard, Brittle Material\u003c\/h2\u003e\n\u003cp\u003eSome jobs need more than a hole — they need a shape: a concave hollow, an enlarged opening, a rounded recess ground into glass or stone. On hard, brittle material, a standard bit chips and cracks long before it gets there. The Proxxon No. 28234 is built for exactly that work: a diamond-coated ball bit that grinds, mills, and shapes glass, ceramic, porcelain, and stone up to granite, cleanly.\u003c\/p\u003e\n\u003cp\u003eThe 3.2mm spherical head is the whole point. Its round profile is ideal for concave grinding, hollowing, freehand shaping, and enlarging or smoothing existing holes — the contouring work a straight drill bit simply can't do. The diamond coating abrades rather than punches, so it works into the hardest, most fracture-prone surfaces without the chipping that ruins a piece, and the standard 2.35mm (3\/32\") shank drops straight into Proxxon MICROMOT collets and other rotary tools.\u003c\/p\u003e\n\u003cp\u003eAs with any diamond bit on brittle material, low and wet wins: run it around 2,000 RPM with water or coolant on a drill press for the cleanest results and the longest bit life. It comes as a 2-pack. For fine detail and starting small precision holes, pair it with the smaller \u003ca href=\"\/products\/proxxon-diamond-drilling-grinding-bit-1-0mm-no-28230\"\u003e1.2mm diamond bit\u003c\/a\u003e — the ball shapes and hollows, the fine bit handles the delicate detail. This bit is also one of the diamond consumables in the \u003ca href=\"\/products\/proxxon-distar-cut-polish-essentials-kit-lwb-a-wp-a\"\u003eProxxon-DiStar Cut \u0026amp; Polish Essentials Kit\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eWhy Tile Pros Choose It\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eShapes what won't drill flat:\u003c\/strong\u003e Concave grinding, hollowing, and enlarging holes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCuts hard, brittle material:\u003c\/strong\u003e Glass, ceramic, porcelain, and stone up to granite\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiamond-coated ball:\u003c\/strong\u003e Abrades cleanly instead of chipping or cracking\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUniversal 2.35mm shank:\u003c\/strong\u003e Fits Proxxon MICROMOT and standard rotary tools\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRuns wet:\u003c\/strong\u003e Coolant keeps cuts clean and extends bit life\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2-pack:\u003c\/strong\u003e A spare on hand for the next job\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe bit for when a hole just isn't enough:\u003c\/strong\u003e Contour and shape, handled\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003ePro tip:\u003c\/strong\u003e Let the diamond do the work — light pressure, ~2,000 RPM, and a steady drip of water. For concave grinding, ease the ball in and work it in small circles rather than forcing depth; forcing a brittle material is how you crack it. A drill press gives you the control this kind of shaping needs.\u003c\/p\u003e","brand":"Proxxon","offers":[{"title":"Default Title","offer_id":67587357475061,"sku":"28234","price":9.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0316\/2731\/3284\/files\/28234.webp?v=1790598515","url":"https:\/\/www.tileprosource.com\/products\/proxxon-diamond-drilling-grinding-bit-3-2mm-ball-2-pack-no-28234","provider":"Tile ProSource","version":"1.0","type":"link"}