Milling stainless steel: That's how it works

Milling metals is one of the standard processes in metalworking. However, not every metal can be cut equally well. This applies in particular to steel and stainless steel. If you still want to mill stainless steel as a home improvement, the specifics of each alloy are enormously important.

Stainless steel is not the same as stainless steel

Stainless steel is often equated with stainless or stainless steel. Stainless steel does not necessarily have to be stainless. Rather, the name stainless steel provides information about certain minimum requirements for the alloy. The content of iron compounds such as phosphorus and sulfur must not exceed 0.025 percent according to DIN EN 10020.

The most common stainless steels in do-it-yourselfers

However, most of the stainless steels you are dealing with as home improvement will be stainless steel. Here are the most common alloys to find:

  • 1.4300 (V2A)
  • 1.4401 (V4A)

In addition, V4A is resistant to salt water and chloride-containing media. However, the hardness can also vary with these stainless steels. You definitely need very high-quality machines and milling heads to mill most conventional stainless steels. However, it is important that you always check the hardness when buying stainless steel in order to determine if and which milling cutters are suitable for the respective stainless steel.

Milling stainless steel - the milling machine

First, the milling machine must be suitable for metalworking. A tiller designed for wood is totally unsuitable. So pay attention to a high-quality milling machine with which steel and stainless steel can be milled. Preferably, this also includes that an automatic coolant lubrication occurs during milling.

Suitable milling heads for stainless steel alloys

But also the milling heads must have corresponding properties. Preferably use cobalt-alloyed HSS milling heads type VA (milling heads HSS-Co type VA). In this composition, the milling head dissipates the heat better. If it is not too hard stainless steel, a milling head HSS type N is still possible, but the service life will be significantly reduced again.

The service life depending on the milling task

You can also rough with the mentioned milling heads. If you just want to finish, a solid carbide milling head could be sufficient, but the service life will be greatly reduced. However, it must be mentioned that the service life when roughing is always greatly reduced.

Ultimately, the professional milling of a stainless steel workpiece is always a compromise between tool life and chip removal. The higher the chip removal, the lower the tool life, which ultimately represents a cost issue.

Feed and cutting speed

At the cutting speed with HSS milling heads should be set about 10 to 14 m / min. The feed will be correspondingly low according to the hardness of stainless steel. When milling stainless steel, it is essential to keep in mind that cooling takes place during milling. Preferably, you should take all the data from a Metal Table Handbook based on the specification of this stainless steel.

Tips & Tricks

A similar amount of effort must also be used for other mechanical operations such as grinding or drilling of stainless steel sheet. It may be useful for hard alloys to transfer the work to a specialist metalworking company in your area, as the cost of materials is quite expensive due to the relatively short service life of the drilling and milling heads when machining stainless steel.

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