Cut a thread in stainless steel

Again and again it happens that a thread has to be cut into a metal workpiece. Of course this also applies to stainless steel. However, the special properties of stainless steel are to be considered. In addition, not every stainless steel can be processed accordingly.

Machining stainless steel is a challenge

The mechanical processing of stainless steel brings the tools and aids to the limits of their resilience quickly, especially in do-it-yourselfers. Even drilling into a stainless steel sheet can be a real challenge. However, stainless steel is not the same as stainless steel:

  • stainless or stainless steel
  • particularly hard stainless steel alloys (not necessarily stainless)
  • cold or hot strengthened stainless steel

Do-it-yourselfers usually work on the following stainless steels

Do-it-yourselfers usually use stainless or stainless steel. According to DIN EN 10020 these are the alloy types 1.4300 (colloquially or as brand name often also V2A) or 1.4401 (V4A). These are cold strengthened stainless steels that can be machined without difficulty with the right tool.

Suitable for stainless steel taps and drills

Regardless of whether you want to cut by hand or by machine, whether it is an internal or external thread, it is urgently necessary to use a suitable cutting tool for threading HSS. In addition, the dies or taps should be especially suitable for stainless steel.

The right coolant is a crucial success factor

The bevel, ie chip spaces and clearance angles, are specially adapted to the properties of stainless steel here. In addition, cooling is especially important in thread cutting. Do not use a conventional emulsion, but a high quality cutting oil, which really has outstanding cooling properties. The higher the quality of the coolant, the better it will be to cut threads in stainless steel.

Cutting speed for stainless steel

If machine tapping in stainless steel still the speed as an important factor. Compared with conventional steels such as structural steel, etc. (eg ST37), the speed must be at least halved as a rule of thumb. Once again we want to point out the importance of cooling.

Consider special features of the alloy and the borehole

In addition, of course, the choice of the right tap is crucial if you want to cut a thread on a through hole or a blind hole. Through-hole drills are likely to break when cutting a thread on a blind hole.

Tips & Tricks

To set the correct feed rate and appropriate speeds, you should know exactly which stainless steel alloy your workpiece is. In addition, in addition to a suitable cutting tool for tapping a table book metal is recommended to align all the requirements exactly on the existing stainless steel can.

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