About This Complete 24-Piece Diamond Drill Bits Set: Includes 5 pieces each of 1mm, 1.5mm, 2mm, and 2.5mm, plus 4 collets. Perfect jewelry drill bits for precision holes in glass, stone, sea shells, gemstones, and other hard materials. Durable Diamond Tipped Drill Bit Design: Each bit features a diamond coating and 135° split point, reducing walking while delivering accurate, clean drilling in tough materials like ceramic, rock, and glass. Wide Compatibility & Versatility: Works as a diamond dremel bit with rotary tools, drills, flex shaft attachments, and lapidary equipment. Bonus collets ensure a secure fit for all your jewelry making tools. Ideal for Crafts & Jewelry Projects: Transform sea glass, shells, and natural stones into unique designs. These dremel diamond drill bits are essential jewelry making supplies for DIY crafters and professionals. Engineered for Hard Surfaces: Reliable performance when using diamond drill bits for stone, glass, ceramic, and minerals. Achieve smooth results with these precision dremel drill bits for creative and professional applications. Drilax Quality for Lasting Results: Trusted for jewelry making tools, crafting, and stone work. Depend on Drilax diamond drill bits for glass and stone to create beautiful keepsakes and handmade designs. Overview Material : Alloy Steel, Diamond Cutting Diameter : 1.00, 1.50, 2.00, 2.50 Millimeters Finish Type : Diamond Coated Shank Type : Straight Cutting Angle String : 135 Degrees