The dimensional accuracy of machine tool castings depends on the strict degree of process design and process control. The higher the dimensional accuracy of castings, the stricter the control of factors, and the correspondingly higher casting production costs. There are scientific standards to coordinate the requirements of both the supplier and the demander.

The Chinese standard "Tolerance of Castings" adopts the "Tolerance System of Castings" of the ISO8062-1994 edition. It is the basis for designing and inspecting the size of the parts. It specifies various cast metal and alloy machine tool castings, cast iron boxes, inspection platforms produced by sand casting, metal casting, low pressure casting, pressure casting, investment casting and other methods. The dimensional tolerances include the basic dimensional tolerances of the castings. The specified tolerances refer to the tolerances that can usually be achieved under normal production conditions.

cast iron box

The basic size of the machine tool casting is the size given on the casting drawing, which should include the machining allowance. The tolerance zone should be symmetrically distributed. When there are special requirements, it can also be arranged asymmetrically, and it should be indicated on the drawing or specified in the technical document. Assemble the platform, the pyrotechnic platform wall thickness difference can generally be reduced, for example, the general dimensional tolerance on the drawing is CT10, and the wall thickness tolerance is CT11. When the wrong box value is to be limited, the big wrong box value should be marked.

The basic characteristics of the casting process of machine tool castings: the filling speed and pressure can be adjusted appropriately. There are two types of casting molds used for casting of large-scale machine tool castings: metallic molds and non-metallic molds. Metal molds are mostly used for large-scale and mass-produced non-ferrous metal castings. Non-metallic molds are mostly used for single-piece small-batch production. For example, sand molds, graphite molds, ceramic molds and molten mold shells can all be used for low-pressure casting, and they are mostly used in production. It's still a sand mold. However, the air permeability and strength of the sand moulding material used for large-scale machine tool castings should be higher than that of gravity pouring. The gas in the cavity is exhausted by exhaust ducts and sand pores.

Jinggong Measuring Tools Producing Co., Ltd is specializing in manufacturing and exporting all kinds of cast iron products，especially for cast iron floor plates, cast iron surface plates, cast iron clamping plates, cast iron angle plates, cast iron box table and other machine tool castings. Our engineering enables us to design the cast iron plates and tables according to DIN Standards, Indian Standards and Chinese Standards, machining by CNC machine tools and install in the world market.