28 pcs 3-30mm Nylon Bead Rounding Concave Holder 6mm shank for Polishing Jade Bodhi Seeds Walnuts

Nylon Concave Bead Rounding Holders (28-Piece Set, 3–30 mm)

Engineered as precision non-marring rotary fixtures for holding, rounding, and mirror buffing spherical beads, organic craft materials, and lapidary gemstones. Made from high-density engineering nylon, these concave cup holders securely cradle beads during high-speed rotation, preventing surface scratches, edge chipping, or thermal damage.

Technical Specifications

• Product Type: Rotary Bead Polishing Jigs / Concave Cup Holders
• Body Material: High-Density Non-Abrasive Engineering Nylon Plastic
• Shank Diameter: 6 mm (approx. 1/4 inch) solid steel arbor mandrel
• Set Assortment: 28-piece progressive set from 3 mm to 30 mm outer diameter (1 mm increments: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 mm)
• Polishing Media Compatibility: Non-abrasive carrier designed to be paired with diamond lapping pastes, cerium oxide slurries, or fine buffing compounds
• Sanding & Polishing Applications: Spherical bead rounding, surface gloss enhancement, rotary contouring, and scratch removal
• Suitable Workpiece Materials: Jade, amber, beeswax, turquoise, agate, bodhi seeds, walnuts, hardwood beads, and organic crafts
• Machine Compatibility: Hand electric drills, bench drill presses, flexible shaft rotary machines, and die grinders with 6mm collets

Key Characteristics

• Non-Marring Soft Protection: Wear-resistant nylon matrix protects delicate polished spheres from gouging, metal marking, or micro-cracks.
• Comprehensive Size Coverage: Continuous 3mm to 30mm range accommodates miniature beads up to large prayer beads and decorative spheres.
• High Rotational Concentricity: Fitted with true-running 6mm steel shanks for stable, vibration-free spinning in hand and drill presses.
• Compound Retention: Concave cup design naturally retains polishing paste and lubricants for efficient, clean finishing.

Operational & Safety Guidelines

• Mandrel Insertion: Insert the 6mm steel mandrel completely into the drill chuck before tightening to prevent shaft deflection or runout.
• Usage Technique: Apply a small dab of diamond polishing paste or buffing compound directly inside the nylon cup or onto the bead surface. Run drill at moderate RPM while rotating the bead against the cup for uniform spherical finish.

Recommended Applications

• Lapidary & Gemstone Jewelry: Rounding and polishing spherical jade beads, agate marbles, amber drops, and turquoise cabochons.
• Traditional Craft Finishing: Polishing Buddhist prayer beads, bodhi seed bracelets, walnut shells, and exotic hardwood spheres.