Granite tri square

Granite tri square Cast Iron Measuring Tools granite angle plate DESCRIPTION Granite tri square made of Jinan black granite, which is with high density, good quality. There are two small side lapped measuring surface. emm) Squareness between measuring surface and datum surface Flatness and straightness of measuring surface Flatness and straightness of datumsurface Precision Grade (μm) 00 0 00 0 00 0 100×63 2 4 1 1 1 1 160×100 2 4 1 2 1 1 250×160 2.5 5 1 2 1 2 400×250 3.5 7 1