The High Speed Steel Burs, Size 20 (5 mm) Heart 45° is a heavy-duty precision bur crafted for professional jewelers who require maximum power, accuracy, and durability during stone setting and advanced metal shaping. Made from top-grade High Speed Steel (HSS), this bur delivers exceptional hardness, prolonged sharpness, and stable cutting performance even under demanding high-speed use.

This bur features a 45° heart-shaped cutting profile, designed for creating accurate stone seats, controlled undercuts, deep reliefs, and smooth contours. The larger 5 mm (Size 20) diameter provides significant cutting depth and efficiency, making it ideal for large stone settings, structural shaping, wide seat formation, and aggressive material removal—while still maintaining professional precision.

Its spiral-cut flute design ensures optimal chip removal, prevents clogging, and reduces heat buildup, resulting in smoother, cleaner cuts. The 3/32″ (2.35 mm) shank ensures full compatibility with major rotary jewelry tools, including flex shafts and micromotors.

Whether used for setting oversized gemstones, carving deeper channels, or shaping metal for custom designs, this Size 20 heart bur delivers exceptional performance and reliability for bench jewelers and stone setters.

Key Benefits

• High-Grade Durability: Crafted from High Speed Steel for superior wear resistance, hardness, and long tool life.

• Precision 45° Heart Angle: Ideal for creating strong stone seats, controlled shaping, and professional-grade undercuts.

• Smooth & Efficient Cutting: Spiral flutes reduce clogging, improve chip flow, and maintain cooler cutting temperatures.

• Large 5 mm Diameter: Size 20 provides deep, efficient shaping for larger settings and heavy metal removal.

• Industry Standard Shank: 3/32″ size fits all professional rotary tools used in jewelry workshops.

• Professional Performance: Ensures clean contours, secure seat formation, and reduced finishing time.