The North Heavy Machinery surface plate is an instrument that reproduces values in a fixed form, making it a physical measuring tool. The working surface of the plate is often used as a planar reference to calibrate and adjust other measuring instruments or to serve as a standard for comparison with the measured part. It is specifically designed for form and position error measurement, hence it is a form and position error measuring instrument.
A surface plate is a planar reference instrument used for workpiece inspection or marking. This definition indicates the nature, function, and purpose of the surface plate. It is an instrument that reproduces values in a fixed form, making it a physical measuring tool. The working surface of the plate is often used as a planar reference to calibrate and adjust other measuring instruments or to serve as a standard for comparison with the measured part. It is specifically designed for form and position error measurement, hence it is a form and position error measuring instrument. The naming of the surface plate also specifies its specific purpose—used for workpiece inspection or marking.
Surface plates are the most commonly used reference positioning instruments in mechanical measurement. Larger-sized clamping plates, when installed on specialized supports, are collectively referred to as platforms. Commonly used types include cast iron surface plates and rock material plates. Based on the flatness value of their working surfaces, surface plates are divided into five accuracy grades: 00, 0, 1, 2, and 3. The smaller the value, the higher the accuracy. They are categorized by material into steel surface plates, cast iron surface plates, rock surface plates, marble surface plates, and granite surface plates. By structure, cast iron surface plates are divided into ribbed plate type and box type, while rock surface plates are divided into flanged and non-flanged types. By purpose, they are classified as inspection surface plates, marking surface plates, and sand-pressing surface plates. By accuracy level, they are divided into 00, 0, 1, 2, and 3 grades, with grades 2 and above being inspection surface plates and grade 3 being marking surface plates. The smaller the value, the higher the accuracy. This classification further ensures the process performance and intrinsic quality of high-precision surface plates.