Niqua® 77 Tool Steel Burs Oval

Shape curved concave hollows, blend smooth transitions, and machine organic contours in precious metal mountings without leaving flat facets or chatter marks. Manufactured to Swiss-Made standards for NIQUA, the NIQUA® SUPER Q® Oval Bur "77" (Ovalfräser) is a heavy-duty rotary milling and contouring cutter engineered for professional stone setters, goldsmiths, and sculptors.

Featuring a robust, egg-shaped elliptical cutting head with deep radial fluting and circumferential contour relief, the Series 77 bur provides smooth transitional cutting across three-dimensional curvatures. Its convex profile allows the bur to sweep across domed surfaces, hollow signet ring galleries, and large bezel cavities while maintaining continuous, low-vibration contact. Forged from premium hardened tool steel, each bur retains sharp cutting teeth and resists tool loading in gummy, ductile precious metals such as yellow gold, sterling silver, copper, brass, and related non-ferrous alloys. Fitted with an industry-standard 2.35 mm (3/32") shank, these large-diameter oval burs mount directly into jeweler flexible shaft handpieces, heavy-duty bench micromotors, and quick-change chuck systems. Available in substantial finishing diameters of 6.00 mm, 7.00 mm, and 8.00 mm (Art.-No. 03 240 060 to 03 240 080), each size is packaged in a protective bench storage box containing 6 pieces.

Why Choose NIQUA® SUPER Q® 77 Oval Burs

• Distinctive Elliptical Oval Profile: Egg-shaped geometry transitions smoothly between curved bottoms and steep sidewalls, preventing the gouges often caused by cylindrical or sharp-edged wheel cutters.

• Broad Surface Contact Area: The gentle curvature spreads milling pressure evenly across metal surfaces, delivering clean, homogeneous finishes and cutting hand-finishing time.

• Deep Swarf Evacuation Flutes: Engineered flute gullets rapidly clear chips outward during heavy stock removal, preventing tool clogging and galling in soft gold and silver.

• Low-Vibration Concentric Operation: Precision-ground tool steel core minimizes radial runout, eliminating chatter marks during heavy hollow milling.

• Hardened Swiss-Quality Tool Steel: Formulated for maximum edge retention, wear resistance, and long service life across continuous workshop use.

• Universal 2.35 mm (3/32") Shank: Provides seamless compatibility across standard flexible shaft handpieces, quick-change chucks, and laboratory micromotors without collet adapters.

Size Selection Guide