Granit in metrology
Black granite, thanks to its properties, has found in recent years a very wide use both in the field of traditional control instruments (planes, lines, teams), as well as in three-dimensional measuring machines and operators with unconventional processes.
The surfaces in black granite, suitably lapped, as well as ensuring considerable precision, allow excellent results when sliding on air cushions.
The Microplan Group, through its production sites in Italy (Microplan Italia Srl) and France (Microplan France Sas), manufactures:
Granite bases
for coordinate measuring machines (CMMs), with the ability to produce small, medium, and large bases (up to 50 tons)
Crossbeams and Z-axes for CMMs
in ceramic (alumina and silicon carbide SiSiC), with the capability to produce parts up to 3800 mm in length
Calibration masters
in granite and ceramic (ballbar)
Precision instruments
in granite and ceramic (surface plates, squares, straightedges, prisms, cubes, cylinders, etc.)
Custom measuring benches
for non-standard or critical measurements: Microplan designs and builds custom solutions based on specific customer requirements
Electronic instruments
for geometric and dimensional checks (straightness, flatness, squareness, squaring, cylindricity, roundness, large-diameter measurements, etc.)
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Materials
The reasons behind the choice of black granite for manufacturing ultra-precision components are:
Dimensional stability
Granite is a naturally aged material, having formed over millions of years, and is therefore free from internal stresses.
Thermal stability
Granite’s linear expansion coefficient is significantly lower than that of steel or cast iron.
Hardness
Granite hardness is comparable to that of good-quality hardened steel.
Wear resistance
Its hardness ensures longer tool and base lifespan over time.
Machining precision
Granite enables the achievement of surface flatness beyond what traditional materials can offer.
Resistance to acids, non-magnetic, electrical insulation, oxidation-proof
Granite is chemically inert, non-magnetic, insulating, corrosion-resistant, and requires minimal maintenance.
Cost
Thanks to modern manufacturing processes, granite-based instruments have become more cost-effective than metal ones.
Recalibration
Our granite tools can be periodically reconditioned quickly, restoring their original accuracy and extending service life — eliminating end-of-life issues.
Download the technical data sheets for metrology-grade materials:
Superior properties of absolute black granite
Our absolute black granite GNU | CR5 offers significant advantages over Black Africa granite in the production of metrological bases and measuring instruments.
Thanks to its superior dimensional stability and compactness, GNU absolute black granite ensures long-term precision even under critical operating conditions.
This material also features lower porosity, reducing moisture absorption and increasing wear resistance.
Its high hardness and geometric precision make it ideal for manufacturing metrology tools such as surface plates, measuring instruments, and bases for coordinate measuring machines (CMMs), ensuring outstanding quality and long-lasting durability.
Surface excellence for metrology applications
Absolute Fine black granite stands out for the superior quality of its surfaces, achieved through an extremely precise lapping process.
This treatment ensures perfectly flat surfaces — essential for optimal performance in metrology applications — and enables smooth, consistent motion for air bearing systems, such as coordinate measuring machines (CMMs) and fully customized turnkey measuring benches specifically designed around the customer’s requirements.
In all industrial sectors where precision is critical, a finely finished black granite surface minimizes geometric errors, ensuring reliable and repeatable measurements.
Thanks to its homogeneous and compact structure, it offers high stability and surface accuracy, making it an essential choice for those seeking maximum reliability in metrological measurements.
Low porosity and resistance to contamination
Absolute fine black granite: precision and elegance in a single material
Absolute black granite is not only synonymous with high technical performance, but also stands out for its uniform color and consistent appearance — qualities that make it ideal for applications requiring both precision and aesthetic value.
This combination of technical and visual properties makes absolute black granite an excellent choice for the production of metrology instruments, machine bases, and inspection surfaces.
Its perfectly black, compact, and flawless surface ensures maximum dimensional stability, while also delivering a visual impact that conveys precision and quality.
Why choose black granite?
Black granite is the perfect material for the production of small and medium-sized bases and metrology instruments such as surface plates, straightedges, squares, cubes, and parallelepipeds.
Its selection is driven by its exceptional technical properties, making it indispensable in applications where the following are required:
- Flatness: perfectly flat surfaces for high-precision measurements.
- Dimensional stability: resistance to environmental variations, ensuring consistently reliable measurements.
- Precision for air bearing systems: ideal for applications using air-cushioned slides, providing smooth and frictionless movement.
Thanks to these properties, black granite and absolute black granite are widely used in metrology laboratories, mechanical industries, and applications where measurement quality is essential.
Improved mechanical properties
Ensure stability and reliability in the most demanding industrial applications.
Superior dimensional stability
Delivers consistent precision even under high loads or environmental changes.
Excellent geometric accuracy
Ideal for industrial applications requiring tight tolerances and greater wear resistance.
Excellent flatness results
Improves performance, especially in air bearing applications.
Reduced surface roughness
Ensures smoother surfaces than other granites, thanks to a uniform structure.
Low porosity
Makes the material resistant to moisture and contamination.
Uniform and compact aesthetic appearance
Visual homogeneity enhances the company’s image as well.
Industrial application fields of absolute black granite
Absolute black granite for coordinate measuring machines and machine tools
Applications in metrology
Thanks to its properties, absolute black granite is the preferred choice for:
- CMM bases: Provides a solid and stable foundation for coordinate measuring machines, essential for ensuring measurement accuracy.
- Measuring instruments: Ideal for manufacturing surface plates, straightedges, squares, and other metrology tools requiring long-term precision and reliability.
- High-precision machine tools: Used as a base for precision machine tools, it helps reduce vibrations and maintain accuracy during operations.
Distinctive technical features of absolute black granite
- Dimensional and thermal stability: Absolute black granite is free from internal stress and has a lower thermal expansion coefficient than materials such as cast iron and steel, ensuring precise measurements even in environments with thermal variations.
- High hardness: With a hardness comparable to that of quality hardened steel, it offers superior wear resistance, ensuring long service life of bases and measuring instruments.
- Homogeneous and compact surface: The fine grain and uniform coloration of absolute black granite allow for excellent surface finishing, essential for high-precision metrology applications.
Economic advantages
The use of absolute black granite not only enhances the performance of tools and machines but also reduces ordinary maintenance costs thanks to its durability and wear resistance.
In conclusion, absolute black granite is an excellent solution for the needs of modern metrology, combining precision, stability, and longevity.
Microplan Group: experience and quality in selecting the finest granites
In the field of precision mechanics and metrology, the choice of material for the production of bases and precision components is crucial.
Each type of granite has its own physical and mechanical properties, making it ideal for applications requiring high stability, precision, and long-term durability.
With nearly 50 years of experience in the industry and in-depth knowledge of materials, the Microplan Group has developed a network of carefully selected partner suppliers, ensuring a constant supply of high-quality materials.
These partnerships allow us to efficiently meet our customers’ needs, always offering materials optimized for the required machining specifications.For each project, the Microplan Group analyzes the customer’s needs and recommends the most suitable type of granite based on:
- Required tolerances: materials selected to ensure long-term precision and stability.
- Use (intensive or non-intensive): we recommend resistant materials for heavy-duty applications or more economical ones for lighter use.
- Product dimensions: we select the material based on the final size of the part, minimizing waste and optimizing machining and transport.
- Final destination: for large parts, we suggest European-origin granites to reduce transport costs.
The use of granite from European sources not only ensures high quality, but also reduces environmental impact by lowering emissions related to block transportation.
This focus on sustainability translates into economic benefits for our customers, without compromising machining quality.
Trusting the Microplan Group means choosing experience, quality, and a responsible approach to material management.
Certified conflict-free materials: ethics and sustainability
African black granite
Absolute black granite
Blue Lanhelin granite
