Hey all. New here, been lurking and learning for a while and have had fairly good results with my first week on CNC with some plastics and wood. I tried to do some brass today in an attempt to finish up a gift for my girlfriend for Christmas. No luck due to tool breakage. Would really like to be able to get it done in time!

The pieces I am cutting are from 3mm brass. Mostly ground down to result in 1mm sheets with 2mm pegs sticking out. I broke my only 2mm end mill and two 1.1mm carbides. I believe I had the feedrate set too high at first on the 2mm, at 50mm/s. I went down to a tiny 4mm/s on the 1.1mm end mills but they still broke almost instantly. RPM was maxed at 20,000 and I was using pass depths and stepover of just 0.2mm. All bits broke on the very first stroke. Any suggestions?
Cheers