Page 8 - Die_and_Molds_User_Guide_7861458_2017
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Stainless Steels
                     Martensitic stainless steels (AISI 420, 420F) are widely used for producing plastic molds, especially,
                     for cavities of small to medium sizes with complicated shapes and substantial differences in cross-
                     sections. They are supplied as annealed to HB 200, and their heat treatment after machining is

                     Alloy Steels and Plain Carbon Steels
                     Alloy and even plain carbon steels are used for various general parts such as holders, pillars, pins,
                     rings, etc. Moreover, in many cases (low-run production dies, some kinds of molds) AISI/SAE
                     4130, 4140 and 4150 steels are main materials for forming parts. These three steels are usually
           Die and Mold Materials
                     supplied in an annealed state or pre-hardened to HRC 32-35 and can be hardened to HRC 44-52.
                       The die and mold industry handles practically all types of engineering materials, but the most typical
                       for the branch are tool steels.

                     Cast Iron
                     Cast iron (especially grey) is also considered as a die and mold material for manufacturing large-
                     sized parts, plates, spacers, bushings and other components where wear is not expected. In
                     addition, nodular cast iron sometimes is used for dies, punches, jigs and pads and even for molds.

                     Nonferrous Metals
                     Aluminum is not the most popular material in the die and mold industry, but it often used for
                     prototype dies and molds, for multiplied identical molds, short life molds and various extrusion
                     molds because it is easy to machine and low cost. Today aluminum starts to penetrate into resin
                     mold manufacturing due to its much better thermal conductivity, machinability and polishability
                     compared to mold steels. The following aluminum alloys: 2024, 6061 and 7075 (in accordance
                     with the Aluminum Association Alloy and Temper Designation System) are more and more
                     common in mold making practice.

                     Beryllium-copper alloys and zinc alloy are materials for blow molds, injection mold components
                     and cavity inserts. Modern metal producers offer beryllium-copper alloys that have enough strength
                     and good wear and corrosion resistance properties. In machining, they are cut 2-3 times faster
                     than tool steels. The alloys’ hardness is HRC 30-42, depending on the hardness grade. For this
                     reason the beryllium-copper alloys can replace traditional tool steels and stainless steels as a mold
                     material in some cases.

                     Electrical discharge machining (EDM) is another important field of nonferrous metals application
                     in die and mold making. Electrodes for EDM are produced from brass, copper, copper tungsten
                     (60-70% of tungsten) and graphite.

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