Item Surface Plate Material Granite Application Grade Inspection Color Gray Edge Style Flat Flatness 0.00015 in/0.0038 mm Grade A Length 24 in Surface Size 24 in x 36 in 600 mm x 900 mm Thickness 4 in Flatness Unilateral Tolerance (In.) 0.00012 Flatness Unilateral Tolerance (mm) 0.0030 Standards GGG-P-463c Surface Size (In.) 24 in x 36 in Surface Size (mm) 609 mm x 914 mm Weight (Kilograms.) 200 kg 36 in Weight (Lbs.) 17 lb