I. Core Material and Innate Advantages
Mainly using Jinan Green fine-grained black granite, naturally aged for hundreds of millions of years with no internal stress, offering outstanding advantages compared to cast iron reference plates:
Ultra-low thermal expansion: Thermal expansion coefficient 2.5~4.6×10⁻⁶/℃, almost no deformation under temperature changes, suitable for constant temperature metrology, optics, and semiconductor scenarios;
High rigidity and wear resistance: Shore hardness HS70 and above, difficult to scratch, rust-proof, and non-magnetic;
Vibration damping and stability: Dense crystal structure, vibration-resistant, with good measurement repeatability;
Deformation resistance: Long-term heavy loading and ambient temperature environments maintain stable flatness.
II. Integrated Installation Hole Structure (Core Customization Item)
- Two Mainstream Integrated Hole Solutions
(1) Embedded Stainless Steel Threaded Inserts (Most common, grid installation holes)
High-strength stainless steel threaded inserts are embedded in the working surface of the platform, rather than tapping directly into the stone, to avoid screw cracking or stripping:
Standard thread specifications: M6/M8/M10/M12 (Metric); 1/4-20, 3/8-16 (Imperial)
Grid spacing: 50/100/150mm standard matrix, non-standard layouts available upon request
Machining precision: Hole position tolerance ±0.1mm, threaded insert countersink 0.5~1mm below the surface, overall grinding after completion to preserve flatness
Process: CNC diamond water-cooled drilling → gluing and embedding stainless steel bushings → constant temperature grinding of the entire surface → laser detection of hole positions
(2) Precision Reamed Holes (Locating through holes / Countersunk installation holes)
High-precision reference reamed holes such as 8H7, 10H7, used for locating pins, columns, and tooling positioning, with hole diameter tolerance ±0.015mm, high perpendicularity, compatible with fixtures, displacement stages, and height gauge bases. - Mandatory Process Specifications for Hole Opening (Crack Prevention)
Hole edge distance from stone side ≥50mm, hole-to-hole spacing ≥100mm to disperse stress;
Full water-cooled diamond tool machining throughout, dry drilling is prohibited;
Thickened plates (thickness ≥100mm) for large-sized platforms to enhance the structural strength of the hole opening;
Countersunk holes for bracket fixing can be processed simultaneously at the bottom for locking the platform floor bracket.
III. Accuracy Grades (National Standard GB/T20428, DIN876)
Таблица
Accuracy Grade Flatness Tolerance (μm/m) Applicable Scenarios
Grade 000 ≤1.5 Nano-optics, CMM reference, metrology laboratories
Grade 00 ≤3.0 Precision component inspection, laser interferometry, automated tooling bases
Grade 0 ≤6.0 Mold inspection, machine tool calibration, conventional precision measurement
Working surface roughness Ra≤0.32μm, mirror-polished, clean and free of sand pits or cracks.
IV. Типичные сценарии применения
Precision Inspection: Height gauge, dial indicator base, component scribing, geometric tolerance inspection;
Automation Equipment: Vision inspection platform, guide rail base, fixture quick-clamping table;
Optical Laboratory: Optical path reference table, displacement slide installation, interferometer base;
Metrology / CMM Accessories: Standard reference plate, tooling positioning base;
Semiconductor / Lithium Battery: Wafer inspection, battery cell dimension measurement high-precision workbench.
V. Optional Accessories
Adjustable Vibration-Damping Bracket: Cast iron bracket leveling feet, paired with anti-vibration pads, for rapid platform leveling;
Bottom Mounting Holes: Pre-embedded threaded holes on the bottom surface, for overall fixing to the machine tool base;
T-Slot Composite Structure: Tabletop features both grid threaded holes and T-slots, compatible with various fixtures;
Protective Sealing: Glazed stone treatment, resistant to oil stains and water seepage;
Chamfer / Rounded Corner: R5 rounded corners around the working surface, to prevent bumping and chipping.
VI. Usage and Maintenance Key Points
Do not over-tighten the locking screws to prevent threaded sleeve loosening and stone cracking;
Clean with anhydrous alcohol and a lint-free cloth, and prohibit hard metal scratching the tabletop;
Avoid single-point impact from heavy objects, and choose thickened load-bearing areas for handling and lifting;
Use a dust cover for long-term storage, and keep away from high temperatures and corrosive acid/alkali environments.
VII. Custom Parameter Selection Reference
Dimensions: Small 100×160mm (height gauge base) ~ Large 3000×6000mm equipment base;
Thickness: 30~300mm, the more holes and larger the size, the thicker the required plate;
Hole Types: Full grid threaded holes, partial threaded holes, single-side positioning light holes, bottom-surface fixing countersunk holes;
Precision: 0/00/000 grade as required, accompanied by flatness and hole position accuracy inspection reports.
