Granite Surface Plate Din876 Grade 00

A granite surface plate is an essential tool in precision measurement, offering a stable, flat reference surface for inspection, calibration, and layout tasks. Its natural durability, accuracy, and resistance to environmental factors make it ideal for industries where precision is paramount, such as aerospace, automotive, and industrial manufacturing.

Maintenance and Care:

• Cleanliness: Surface plates should be kept clean and free of dust, oil, or other contaminants. Even tiny particles can affect the accuracy of measurements.
• Regular Calibration: Despite their durability, granite plates need regular recalibration to ensure they maintain their flatness, especially in high-use environments.
• Proper Storage: When not in use, surface plates should be covered to protect them from dust or damage.

Key Features of a Granite Surface Plate:

1. Material:

   • Granite is used because of its hardness, density, and resistance to wear and corrosion. It is not as affected by temperature changes as metal, which makes it highly dimensionally stable.
   • The granite used is typically black granite, chosen for its fine grain structure, minimal porosity, and excellent resistance to wear.
   • Non-magnetic and non-conductive, granite does not interfere with magnetic or electronic measuring instruments.

2. Flatness and Accuracy:

   • The primary function of a granite surface plate is to provide a reference flat surface. Granite surface plates are manufactured to very tight tolerances, with variations in flatness measured in microns (millionths of a meter).
   • These plates come in different grades of accuracy:
     • Grade 00 (Laboratory Grade): The highest accuracy, used in metrology labs.
     • Grade 0 (Inspection Grade): Suitable for precise inspection work in factories and labs.
     • Grade 1 (Toolroom Grade): Used in general manufacturing and toolrooms for less critical measurement and layout tasks.

3. Dimensional Stability:

   • Granite surface plates are highly stable over time and are resistant to warping, bending, or expanding due to changes in humidity or temperature.
   • The natural material resists wear better than metal plates and maintains its flatness over long periods of use.

4. Size:

   • Granite surface plates come in a wide variety of sizes, from small plates used for bench work (e.g., 300 mm x 300 mm or 12 inches x 12 inches) to large plates for industrial use (e.g., 2000 mm x 3000 mm or 6 feet x 10 feet).
   • Plates are available in both metric and imperial dimensions, depending on the specific needs of the industry or region.

5. Calibration and Traceability:

   • Granite surface plates are calibrated against reference standards to ensure that they meet specific flatness and accuracy requirements.
   • Many come with a calibration certificate to show they have been inspected and are traceable to national or international standards, such as ISO 9001 or NIST (National Institute of Standards and Technology).
   • Regular recalibration is recommended to ensure the plate maintains its accuracy, particularly in high-use environments.

6. Resistance to Damage:

   • Granite plates are extremely durable and resistant to damage like scratches, nicks, and corrosion. They are harder than most steels, which makes them ideal for environments with heavy-duty use.
   • If a small area is damaged, it is often localized and does not affect the overall flatness of the surface, unlike metal plates which can warp or dent.

7. Support and Leveling:

   • For proper use, granite surface plates must be supported evenly to avoid any distortion in the flatness. They are usually mounted on special stands or frames with adjustable feet to ensure the plate remains perfectly level.
   • High-precision plates often come with adjustable stands that allow fine-tuning to maintain the plate's flatness under various working conditions.

Technical Specifications