Machinability of 304 Stainless

[DanH45]

304 work hardens really easily.

Sharp bits, good cutting fluid, and feed rate. It takes a while to get a feel for feed rate, too fast and too much heat, too slow and the surface work hardens before you get through.

I found 316 to be quite a bit easier to work with.

 

[stezann]

Soft and tough...no mercy on the feed, clear swarfs, clamp solid the work, cool the cut.
I have had to put a bottlejack under my drill press table to add the necessary rigidity; if everything is going down square is not so easy to break a drill bit, even with 300 series.

 

[james terrio]

If you have a choce for bolsters etc, 304 is the worst as it is 'gummy', free machining grade 303 is better but 416 is the best stainless .416 is the free machining grade of 410.

I've heard of people using 416 for guards and stuff, partly because it machines better but also because you can HT it for better scratch-resistance. I don't know what the correct HT procedure for it would be, but I do know that when you send it to Peters thinking it's 440C and they HT it as such, it comes out at 46Rc.

 

[C L Wilkins]

I've heard of people using 416 for guards and stuff, partly because it machines better but also because you can HT it for better scratch-resistance. I don't know what the correct HT procedure for it would be, but I do know that when you send it to Peters thinking it's 440C and they HT it as such, it comes out at 46Rc.

Additionally, 400 series is more engraver friendly than 300 series.

CW