Round claw tips smoothly, form smooth hemispherical domes on wire ends, and machine clean concave recesses with chatter-free rotary control. Manufactured to Swiss-Made precision standards for NIQUA, the NIQUA® SUPER Q® Cup Bur / Hollow Bur "S(f)" (Hohlfräser) is an essential rotary tool engineered for diamond setters, goldsmiths, and high-end jewelry manufacturers.
Featuring an internal concave hemispherical cavity lined with precision-ground radial flutes and a fine cut (f), this hollow bur caps prongs, rivets, and bezel corners in a single fluid operation. When placed over an uneven or clipped wire stem, the concave cutting chamber shaves down excess height while simultaneously shaping a smooth, rounded dome that will not snag on clothing or scrape skin. Machined from premium hardened tool steel, each bur delivers clean chip evacuation and dependable edge retention in soft, ductile alloys including yellow gold, sterling silver, copper, brass, and related non-ferrous metals. Mounted on an industry-standard 2.35 mm (3/32") shank, these cup burs fit directly into jeweler flexible shaft handpieces, precision micromotors, and quick-change bench systems. Available in a comprehensive size progression from 0.80 mm to 6.00 mm (Item Numbers: 03 230 008), each size is packaged in a bench storage box containing 6 pieces.
Why Choose NIQUA® SUPER Q® S(f) Cup / Hollow Burs
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Precision Hemispherical Cavity: Internal cup profile forms consistent, smooth rounded heads on prongs, posts, and wire ends without flattening the sides.
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Fine Cut (f) Internal Fluting: Closer, finer radial flutes shear ductile metal smoothly, preventing aggressive grabbing or twisting of delicate micro-claws.
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Dual Functionality (Capping & Hollowing): Rounds protruding wire ends externally while the rounded outer head can be used for light concave recessing and cavity smoothing.
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Low-Vibration Concentric Operation: Precision-machined Swiss tool steel core minimizes radial runout, ensuring smooth running and preventing tool bounce against delicate gemstone tables.
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Optimized Chip Clearance: Internal gullets channel swarf outward away from the dome apex, preventing tooth clogging and metal galling in soft gold and silver.
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Hardened Swiss-Quality Tool Steel: Provides wear resistance, edge sharpness, and extended service life across continuous daily bench setting routines.
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Universal 2.35 mm (3/32") Shank: Drops into standard jewelry flex shaft handpieces and micromotor quick-change chucks without requiring collet swaps.
Size Selection Guide
| Diameter (mm) | Item Number |
| 0.80 mm | 03 230 008 |
| 0.90 mm | 03 230 009 |
| 1.00 mm | 03 230 010 |
| 1.10 mm | 03 230 011 |
| 1.20 mm | 03 230 012 |
| 1.30 mm | 03 230 013 |
| 1.40 mm | 03 230 014 |
| 1.50 mm | 03 230 015 |
| 1.60 mm | 03 230 016 |
| 1.70 mm | 03 230 017 |
| 1.80 mm | 03 230 018 |
| 1.90 mm | 03 230 019 |
| 2.00 mm | 03 230 020 |
| 2.10 mm | 03 230 021 |
| 2.20 mm | 03 230 022 |
| 2.30 mm | 03 230 023 |
| 2.50 mm | 03 230 025 |
| 2.70 mm | 03 230 027 |
| 2.90 mm | 03 230 029 |
| 3.00 mm | 03 230 030 |
| 3.50 mm | 03 230 035 |
| 4.00 mm | 03 230 040 |
| 4.50 mm | 03 230 045 |
| 5.00 mm | 03 230 050 |
| 5.50 mm | 03 230 055 |
| 6.00 mm | 03 230 060 |
Free Global Shipping
We process orders within 1-3 business days. Estimated standard international delivery is 6-12 business days.
14-Day Returns
We have a 14-day return policy. Items must be unused, with all original accessories, and in original packaging.
For full details, please refer to our Shipping and Refund policies at the bottom of the page.
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