I am trying to find out how large manufacturing companies grind precision core pins. As a plastic mold maker, I am aware of the manual methods using a surface grinder and Harig type spin fixture and am also familiar with the Ded-Tru machine.
However, these methods are exceedingly slow, albeit quite precise. There just has to be some kind of OD grinder, tool grinder, centerless grinder or special CNC tool grinder that can grind complex mold core pins accurately and with an excellent finish.
But in today, normally the mold maker is not making any pins or insert pins by themselves, you can find some precision components company who specializes in making high precision components, like insert pins and some small inserts, you only need to send them the 3D, 2D drawing and mark the tolerance for each dimension, then they will do the rest quickly and accurately.
But for some other mold components, you may have to do this by yourself.
Another common material for various injection mold components is a beryllium copper alloy also called Mold Max. It has excellent heat transfer qualities, can be polished and is also pre-hardened. All this combines to make it the material of choice for things such as core pins.
However, is beryllium copper/Mold Max safe?
In my experience is depending on which area of mold components you are using for? I made 64 cavities molds which the parts have some small ribs, the customer was a requirement with MoldMax for better cooling, as you know sixth four core inserts made by Mold Max, that is not cheap, but after the second time of mold trial the small ribs start to break, not only one or two but around 10 inserts had broken done, base on my experience on this material, for some small ribs it is not good option to use Beryllium copper, if some deep ribs but have much more space, then that will be better option to use this material, because you will get good cooling to save cycle time.
This covers the topic in detail and my conclusion is that it is basically depending on the part design, Is you have a plastic mold project that may need this service, you are welcome to send me your drawing, we will suggest you some good option for you to make choices this could be safer for your project.