Granite precision square (also known as granite right angle square / straight edge) is a high-precision 90° reference gauge, primarily used for perpendicularity / right angle inspection, machine tool and equipment calibration, tooling positioning, and precision scribing. With its characteristics of non-magnetization, non-deformation, wear resistance, and excellent temperature stability, it is widely applied in fields such as machinery manufacturing, metrology calibration, aerospace, automotive, and precision instruments.
I. Core Application Scenarios
- Precision Perpendicularity and Right Angle Inspection
Workpiece Inspection: Inspecting the right angle and perpendicularity errors of mechanical parts, precision castings, and sheet metal parts, replacing traditional steel squares to avoid magnetization and deformation, suitable for 00-grade / 0-grade accuracy requirements.
Flatness / Parallelism Assistance: Paired with granite platforms to inspect the perpendicularity of adjacent surfaces and the parallelism of reference surfaces of workpieces, using the light gap method to determine gaps, with accuracy reaching the 0.001mm level.
Tooling and Fixture Verification: Verifying the right angle reference of jigs and tooling to ensure clamping accuracy and product consistency. - Machine Tool and Equipment Installation Calibration
Machine Tool Geometric Accuracy Inspection: Used for X/Y/Z axis perpendicularity calibration of CNC machines, machining centers, lathes, and milling machines, inspecting the right angle accuracy of the bed, guide rails, and worktable to ensure three-axis orthogonality.
Equipment Installation Positioning: Installation alignment of precision equipment, automated production lines, and optical instruments, ensuring the perpendicular reference of frames, bases, and installation surfaces to reduce assembly errors.
Coordinate Measuring Machine (CMM) Calibration: Serving as a reference tool to verify the three-axis perpendicularity of CMMs, ensuring the traceability and reliability of measurement data. - Precision Scribing and Machining Positioning
Scribing Reference: Scribing 90° reference lines and positioning lines on precision plates and mold blanks; high hardness and wear resistance ensure clear scribing edges without burrs.
Machining Alignment: Quickly aligning right angles during workpiece clamping, assisting in precision machining positioning for milling machines, grinding machines, and wire-cutting machines to improve batch processing accuracy. - Metrology Laboratories and Quality Control
Value Transfer: Serving as an AA-grade (laboratory grade) or A-grade (inspection grade) reference to calibrate conventional gauges such as steel squares, dial indicators, and spirit levels.
Final Inspection of Precision Parts: Final perpendicularity inspection of critical parts in aerospace, medical devices, and semiconductor equipment, meeting the requirements of high cleanliness, non-magnetization, and high-precision environments. - Special Industry Applications
Aerospace: High-precision right angle inspection of structural parts, fixtures, and tooling, adapting to low-temperature and vibration environments with strong stability.
Automotive Manufacturing: Perpendicularity calibration of molds, welding fixtures, and inspection gauges to ensure vehicle body assembly accuracy.
Precision Optics: Installation and calibration of optical platforms, microscopes, and lithography machines; non-magnetization and non-deformation avoid affecting optical precision.
II. Material and Accuracy Advantages
Material: Preferred natural black granite such as Jinan Green, aged over millions of years, with a uniform texture and dense structure; rust-proof, acid and alkali resistant, non-magnetizing, and non-deforming.
Accuracy Grades:
AA-grade (Laboratory Grade): Accuracy of 0.0006mm/150mm, used for metrology calibration and high-precision inspection.
A-grade (Inspection Grade): Accuracy of 0.0012mm/150mm, used for routine workshop inspection and equipment installation.
Stability: Minimal impact from temperature changes, maintains accuracy under heavy loads, and has a service life far exceeding that of steel gauges.
III. Usage Key Points
Clean the working surface and the workpiece before measurement to remove oil and impurities, avoiding scratches on the reference surface.
Handle with care to avoid bumps and collisions; do not use for striking.or load-bearing. Store in a dry, constant-temperature environment, avoid exposure to strong sunlight and extreme temperature differences, and apply anti-rust oil for protection when not in use for a long time.
