Smooth-Surface Al2O3 Ceramic Lapped Plates Fine Ground Alumina Gauge Blocks for Precision Instrument Parts

Precision instruments rely on reference surfaces that stay flat, smooth and dimensionally stable for decades. Our Smooth-Surface Al2O3 Ceramic Lapped Plates and Gauge Blocks are processed through multi-stage lapping and polishing to reach surface roughness as low as 0.02 microns Ra with sub-micron flatness, producing reference faces that outperform steel gauge stock because ceramic never rusts, nicks as easily, or drifts with temperature as much as metal.

Alumina also brings a practical advantage to metrology: its hardness means handling scratches are far less likely, its low thermal expansion limits temperature induced error, and its electrical insulation suits applications where conductive references are a hazard. Each piece is manufactured and verified in a temperature controlled environment with interferometric flatness checking.

• Mirror smooth surfaces: Polished faces reach Ra 0.02 µm for low friction, low wear precision reference surfaces.
• Sub-micron flatness: Lapping achieves flatness to 0.001 mm, suitable for calibration and inspection tooling.
• Dimensional stability: Low thermal expansion and zero moisture absorption keep size stable across seasons and climates.
• Scratch resistant: Hardness resists handling damage that would ruin the accuracy of softer steel references.
• Non-magnetic and insulating: Safe for use around sensitive electronics and magnetic measurement systems.
• Corrosion proof: No rust or tarnish means no reconditioning and no contamination of measured parts.
• Custom reference geometries: Blocks, plates, rings, angle references and stepped masters made to drawing.

These plates and blocks are used in precision instrument parts such as measuring machine tables, comparator anvils, gauge block masters, optical bench references, coordinate measuring machine staging surfaces and calibration fixtures in standards laboratories.

For metrology equipment manufacturers we can supply matched reference sets with certified flatness and size data traceable to our inspection equipment, including custom shapes for special measuring fixtures.

Reference surfaces are cleaned, protected with soft tissue and stored in fitted foam cases to prevent any contact damage, then boxed for secure shipment.

Each item ships with a verification certificate recording measured flatness, roughness and dimensional values.