If you’ve ever made parts out of stainless steel, you know that it can be a challenge to cut. Not only is stainless hard, but often, if you’re using this material, you want to get a nice surface finish. That combined challenge means there are a few things to consider.
Rigidity Helps
The casting of the Tormach mills provides enough rigidity to make chips out of stainless steel, but you’re only as good as your weakest link. Simply clamping a stainless part in your vise may not provide the rigidity needed to get the surface finishes you want, or even cut properly.
Making sure your fixturing isn’t too small can help prevent chatter. Lesson one for making any cut on a CNC machine is that rigidity in your setup is key.
This means you should create soft jaw workholding that fits your part, use work stops to make sure your parts are seated in exactly the right spot, and don’t get lazy with your workholding.
Obviously, you want to hold your part, but a rigid workholding will make everything go smoother, especially when you’re cutting stainless steel.
Believe It Or Not, Take Heavier Cuts
Don’t go crazy, but taking heavier cuts can help prevent rubbing and recutting of chips, which not only makes your cutting more efficient, but also leads to nicer surface finishes.
That means increasing your feed per tooth, or taking a heavier chip.
Taking heavier cuts means engaging the teeth of your end mill more consistently with the material, which creates a smoother surface finish.
While it might seem counter intuitive to push into a hard material more aggressively, it actually leads to a better cutting experience.
High-Quality Tooling Makes the Difference
While sometimes you just need to get the job done, when you’re cutting stainless, it’s best to make an investment in high-quality tooling.
Generally, you’re better off having end mills with more flutes while you’re cutting something like stainless. This allows you to have more rigidity in the cutting tool, engage the teeth more often, and create smaller chips. Having smaller chips in such a hard material means you can get more cutting out of every tooth which means more efficient cutting.
Also, having more flutes makes it easier to take heavier cuts, which we mentioned earlier would lead to more efficient material removal and a better surface finish.
Tormach offers a line of high-quality tools from Helical that are great for cutting stainless steel.
Use Flood Coolant
When you’re cutting harder materials, there’s the potential for a lot of friction. Your tools and work are bound to heat up, and when steel heats up, it hardens.
Using a flood system to blast your work with coolant will not only help lubricate the friction, but it will also help dissipate some of the heat.
Like with so many things in the world of manufacturing, there is no one fix-all solution for cutting stainless steel on your Tormach mill, but these essentials will give you a head start.
Cutting stainless steel can be a tricky process, so don’t jump in head first! Take your time and dial in your feeds and speeds. While Tormach mills are more than capable of cutting stainless, they aren’t giant VMCs. But, leveraging these recommendations with a fine-tuned feeds and speeds recipe is sure to get you some fantastic surface finishes.
