8" Copper Flat Polishing Lap for Gemstone, Glass & Stone

The 8" Copper Flat Polishing Lap is an expanded-diameter, precision-machined solid copper lap engineered for pre-polishing and fine polishing facets, flats, and large cabochons on hard gemstones, crystals, and optical glass.

Key Features

• Solid Copper Matrix: Pure copper provides the ideal ductility and surface hardness to firmly charge and embed diamond powder, diamond slurry, or lapping compounds without galling.
• Extended 8-Inch Surface: Greater surface area accommodates larger workpieces and provides smoother, faster polishing passes with superior flatness control.
• Precision Flatness: Uniform plate thickness and machined flatness ensure razor-sharp facet junctions and distortion-free optical planes.
• Standard 1/2" Arbor Hole: Seamlessly mounts onto standard 8-inch flat lap grinders, faceting machines, and horizontal lapping units.
• Rapid Heat Dissipation: High thermal conductivity efficiently pulls friction heat away from delicate, heat-sensitive stones during continuous polishing.

Recommended Applications

• Charging with diamond pastes (from 1,200 to 14,000 grit) for pre-polishing corundum (sapphire, ruby), chrysoberyl, quartz, beryl, and tourmaline.
• Facet pre-polishing and precision flat surface lapping on optical glass, crystals, and technical ceramics.
• Large cabochon flat back pre-polishing and metal jewelry finishing.

Operating Guidelines

• Score or cross-hatch lightly if necessary before charging with diamond paste, oil-based extender, or water-soluble lubricant.
• Operate at moderate speeds (approx. 200–500 RPM) to keep lubricant and diamond compound localized on the lap face.
• Clean thoroughly between grit changes to avoid diamond contamination.