Hi guys.
I have a dilemma in my shop.
I don’t have enough inserts for indexable end mill and for face mill . But I have to cut a lot of material from stock steel 4340 . The inserts wear out so quickly. My boss says that I should use low 350 rpm for 3” inches face mill, instead of mine 700 rpm .Even using 700 I can’t cut with high feedrate more than 8 ipm for facing .As soon as I decrease rpm till 500 the loading in the machine jumps suddenly and the process of milling sounds terrible.
I use this face mill for countering milling , but there I have as well heavy loading and terrible sound if the width of cutting 1.5-2 inches for depth 0.030 per pass .
My boss says that high rpm heats the material seriously.
Which parameters or strategies would you recommend for facing and for contour milling to save life of the inserts as long as possible and the same time being the most efficient??