5 Best Diamond Drill Bits For Stone Jewelry | 1.5mm Jewelry Bits

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LASCO’s 1.5mm precision pack is the benchmark for stone jewelry drilling. Each bit uses a stainless steel shank coated in pure diamond with no filler abrasives, creating an edge that cuts through sea glass, agate, and jasper without heating up and seizing. Users report averaging 20 clean holes per bit on sea glass — far exceeding typical electroplated alternatives.

The 1.5mm diameter is the sweet spot for pinch bails and 18-gauge wire, making these ideal for earrings and small pendants. The bits are designed primarily for a drill press, which provides the consistent speed and perpendicular alignment necessary to prevent blowout on thin material. The included storage tube keeps the small bits organized and protected from impact.

While the bits work best under water cooling, several reviewers noted success by starting at a 45-degree angle before straightening to perpendicular. The pack provides ten bits, which translates to roughly 200 holes before depletion — excellent value for a dedicated jewelry maker. A few users reported that bits dull quickly when drilling stone above Mohs 7, but for standard lapidary work, this set is hard to beat.

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The Dremel 664DR FlipBit is a specialized rotary tool bit that flips to provide two hole sizes — 1/16 inch (1.6mm) and 3/32 inch (2.1mm) — from a single shank. This design eliminates the need to swap bits when switching between bail wire gauges, a significant time-saver during production runs of earrings or pendants. The diamond coating is engineered to last five times longer than standard Dremel diamond bits.

This bit excels on glass and softer stone (Mohs 7 and below), with users reporting smooth cuts on wine bottles, sea glass, and tile. The thin profile allows for tight curves and small cuts beyond simple holes. However, multiple reviews caution against using this bit on agate or harder stones, as the thin diamond layer can dull or break under load, even with water cooling.

Customer service from Bosch has been noted as a strong point, with replacements sent for early failures. For those working primarily with softer materials and needing two precise hole sizes in frequent rotation, the FlipBit is an elegant solution. It is not a general-purpose set for mixed stone types, but within its niche, it performs admirably.

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The ZNXIMER set covers five sizes from 3/16 inch to 1/2 inch, making it a versatile choice for mixed materials beyond just stone — think ceramic pots, glass mugs, and porcelain tile. The vacuum brazed technology fuses a thick diamond layer to the steel core, reducing grit loss and wobbling. The anti-slip hex shank fits standard 3/8 inch and 1/4 inch chucks securely.

A standout feature is the included cooling wax, which reduces friction by roughly 60% and minimizes dust, eliminating the need for messy water pans. Users drilling drainage holes in ceramic planters and glass mugs found the bits cut quickly with minimal chipping. The transparent plastic storage case keeps the bits organized but some users noted the paint on the shank can be slightly oversized, occasionally sticking in quick-change chucks.

For a jewelry maker who also handles mixed home projects, this set bridges the gap between precision stone work and general hardware tasks. The hex shank provides excellent grip, and the vacuum brazed construction handles intermittent stone drilling well, though the bits are not as specialized for ultra-fine 1.5mm holes as the LASCO pack.

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The BRSCHNITT set includes four 1/4 inch (6mm) vacuum-brazed diamond bits and one carbide triangular bit for pilot positioning. The 6mm diameter is too large for fine jewelry earrings but works exceptionally well for drilling pendant holes, bead caps, or larger cabochon settings. The hex shank locks into drill press chucks without play, critical for maintaining perpendicularity on small stone pieces.

Users drilling through hard porcelain tile and terra cotta report the bits cut quickly when kept cool with intermittent water dipping. The vacuum brazed technology with #50/60 diamond grit provides aggressive cutting action, making short work of materials like granite and marble. However, the bits are disposable by nature — some users found they wore down after two holes in very hard porcelain, though the value per bit is reasonable at this price point.

For a lapidary artist who needs a dedicated 1/4 inch bit for consistent pendant holes, this set provides four identical bits plus a pilot bit for precise starting. It is not ideal for varied sizes, but for its specific diameter and hex shank stability, it is a solid mid-range option.

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The DECKRKAT 10-piece set offers the widest size range — from 3/16 inch (4.7mm) up to 1/2 inch (12.7mm) — at a very accessible price point. The bits feature a built-in wax lubricant that cools the diamond coating, reducing the friction that typically causes blowout in ceramic and glass. Users drilling drainage holes in planters and shower tile found the bits cut cleanly with minimal chipping when kept wet.

The vacuum brazed diamond technology provides decent durability for light to medium DIY work. The round shank design fits most standard drills, but lacks the grip of a hex shank, making it less ideal for precision work on small stone pieces. Some reviewers noted the bits wear down under heavy pressure or when drilling without water, but for its price, the 10-bit count provides good value for beginners.

This set is best suited for a jewelry maker who also drills drainage holes in ceramic pots or works with larger stone pieces where precision is less critical. The lack of a centering tip requires careful positioning to prevent skating, but with a pilot mark and steady hand, it performs adequately for its cost.