What is the Shape and Structure of a Marble Micrometer?

A micrometer, also known as a gage, is an instrument used for the precise parallel and flat measurement of components. Marble micrometers, alternatively called granite micrometers, rock micrometers, or stone micrometers, are renowned for their exceptional stability. The instrument consists of two core parts: a heavy-duty marble base (platform) and a precision dial or digital indicator assembly. Measurements are taken by positioning the part on the granite base and using the indicator (dial test indicator, dial gage, or electronic probe) for comparative or relative measurement.

These micrometers can be categorized into standard types, fine-adjustment models, and screw-operated models. The foundation of the instrument—the marble base—is typically precision-made from high-grade “Jinan Black” granite. This specific stone is chosen for its superior physical properties:

• Extreme Density: Ranging from 2970 to 3070 kg per cubic meter.
• Low Thermal Expansion: Minimal size change with temperature fluctuations.
• High Hardness: Exceeding HS70 on the Shore scleroscope scale.
• Aged Stability: Naturally aged over millions of years, this granite has completely released all internal stresses, guaranteeing long-term stability without the need for artificial aging or vibration relief. It will not deform or warp.
• Superior Material Qualities: The fine, uniform black structure offers excellent stability, high strength, and remarkable resistance to wear, corrosion, acids, and alkalis. It is also completely non-magnetic.

Customization and Precision Grades

At ZHHIMG, we understand that needs vary. Therefore, we offer customization options for the marble base, including the machining of T-slots or the embedding of steel bushings to accommodate specific fixture requirements.

Marble micrometers are available in three standard accuracy grades: Grade 0, Grade 00, and the ultra-precise Grade 000. While Grade 0 is commonly sufficient for general workpiece inspection, our fine-adjustment and fixed models provide flexibility for various tasks. The large platform allows for easy movement of workpieces across the surface, enabling efficient batch measurement of multiple parts. This significantly streamlines the inspection process, reduces operator workload, and provides unmatched reliability for quality control, making it a highly favored solution among our clients.