Hard milling Tyrax

peon · February 09, 2023, 05:38 AM

Does anyone have any experience rough hard milling Tyrax at 56-58 Rc? We must remove a lot of stock since the profile of these blocks were not roughed. (Grrrr!!!) The core block dimensions are 5 X 9.5 x 4.5 tall. We had best success using the Optirough patch approaching from the outside with a 12mm OSG WXS cutter at .700" DOC X .005" stepover. 141sfm @ .0076 fpt (1146 rpm @ 35 ipm). We are still tearing up cutters. Tyrax is a high chromium stainless. We have great luck hard milling hard 420SS, but this stuff is damn difficult.

RobertELee · February 09, 2023, 06:26 AM

Have you seen this info from Uddeholm? Gives pretty good info on how to rough cavities.

www.uddeholm.com/app/uploads/sites/43/2020/08/C_D_TYRAX-ESR-EN.pdf

peon · February 09, 2023, 07:42 AM

Thanks for the reply! I have seen that. Those recommendations aren't even close to working for us. In fact, I have never seen recommendations from Uddelholm ever work for any of their steel. We successfully machined Stavax, Dievar, Caldie and DC53 and had to veer way off from their advice. Obviously that data isn't tested by them.

RobertELee · February 09, 2023, 09:58 AM

Quote from: peon on February 09, 2023, 07:42 AMThanks for the reply! I have seen that. Those recommendations aren't even close to working for us. In fact, I have never seen recommendations from Uddelholm ever work for any of their steel. We successfully machined Stavax, Dievar, Caldie and DC53 and had to veer way off from their advice. Obviously that data isn't tested by them.

Just curious, but what machine are you running this on?

peon · February 09, 2023, 11:06 AM

Makino F5. If we encounter this again, we will most likely attack the heavy roughing in our OKK VM7 III and move it over to the F5 for finishing. We have finish machined this material in the past, however, we semi-finished within .010"/side before heat treating. This is an outside machining job we took on and the customer didn't rough the material like we would have.

peon · February 10, 2023, 11:51 AM

We have succeeded! Our dedicated hard milling cutters had not been working. We tried our 1" Kyocera Raptor and it roughed with great success!

RobertELee · February 10, 2023, 12:56 PM

Quote from: peon on February 10, 2023, 11:51 AMWe have succeeded! Our dedicated hard milling cutters had not been working. We tried our 1" Kyocera Raptor and it roughed with great success!

High feed and button mills is always the way to go when rough hard milling IMO.