Jour : 06/11/2026

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…

I. First Step: Determine Granite Base Material and Grade (Most Critical)1) Stone Types (From High to Low)Indian Black (M10) / Imported Black Granite: High density, lowest thermal expansion coefficient, best stability, used for high-precision / laboratory-grade CMMs (aerospace, medical, optics).Jinan Green: Top domestic grade, good rigidity and vibration absorption, first choice for mid-to-high-end bridge machines;…