Looking at machining some harder steels - HT 4340 at Rockwell C of 30 and possibly some close to 60. Saw a little on using endmills with small radius on the tips - 0.010 to 0.030 radius. Seems like that would make the end mill less likely to chip. They cost a bit more. What are the pros and cons? Depending on the application the small radius on the inside corner may not be an issue and would lessen the stress riser of the corner.