Firstly, let me introduce today's main topic to all the mold enthusiasts: the selection of milling cutters for mold processing!

In the manufacturing of modern molds, due to the complex structure and high precision requirements of the mold, the surface characteristics and materials of different parts vary greatly, so the milling cutters used for mold processing are also different.

The mold processing process can be divided into rough machining, semi precision machining, precision machining, and sometimes even ultra precision machining. Generally, reversible cutting tools are used for rough machining and semi precision machining processes, while integral cutting tools are used for precision machining processes.

When the mold cavity is a complex three-dimensional surface, the efficiency of contour milling is high, especially suitable for rough machining of the cavity. The commonly used mold processing milling cutters in profile milling include ball end mills, solid carbide ball end mills, etc. The following table compares these four commonly used profile milling cutters in terms of cutting stability, cost productivity, and other aspects.

Next, we will popularize several issues that should be noted when machining curved surfaces with milling cutters for mold processing

(1) Rough milling

The pursuit of material removal rate per unit time should be based on the allowance given by the machined surface, and milling should be done layer by layer with a mold milling cutter according to the same height surface, with high efficiency. Small molds often use integral end mills for processing, while for large molds, considering their economy and processing efficiency, it is recommended to use blade type indexing milling cutters

(2) Semi precision milling

To make the machined surface closer to the theoretical surface, a ball end milling cutter can be used, usually leaving a machining allowance of about 0.5mm for the precision machining process.

(3) Precision machining

Process theoretical surfaces. Generally, integral molds are used to process milling cutters or ball end milling cutters. When precision machining curved surfaces with ball end milling cutters, the line cutting method is generally used. The spindle speed is appropriately increased, the appropriate inflection point is selected, and the tool marks caused by pauses and vibrations are reduced.

(4) Avoid cutting vertically

A good method is to feed diagonally downwards and then cut horizontally with the side edge after reaching a certain depth. When milling groove surfaces, process holes can be pre drilled for cutting.

(5) In milling curved parts, if abnormal phenomena such as poor heat treatment, cracks, and uneven structure of the part material are found, the processing should be stopped in a timely manner to waste time.

(6) Before each start-up milling, the machine tool, fixture, and mold milling cutter should be properly inspected to avoid any malfunctions that may affect machining accuracy or even result in scrap.

(7) When milling the mold cavity, the filing allowance should be appropriately controlled according to the roughness of the machined surface. For parts that are difficult to mill, more filing allowance should be left appropriately; For easily machined parts such as flat surfaces and right angled grooves, the surface roughness value should be minimized as much as possible and filing should be reduced.

In mold processing and manufacturing, the selection of milling cutters for mold processing needs to be comprehensively considered from several aspects such as workpiece material, working conditions, cutting stability, cost productivity, and processing accuracy. Only by reasonably selecting milling cutters for mold processing can we improve processing quality and efficiency, meet product aesthetic and functional requirements, and enhance mold processing technology.