Coating or Substrate Size Range Neck Length Flutes Finish / Rough Page SOLID END MILLS Work Materials Product Name End Mills ap Upper :1st Recommendation Under : 2nd Recommendation G Square End Mill Semi long (ap−4xDC) METRIC DF4JC DC 33−12−4xDC − 4 I254 30° METRIC DFC4JC DC 2.56−12−3.8xDC− 4 For CFRP I252 10° METRIC DFCJRT DC 2.56−12−3.8xDC− 1012 For CFRP I253 Long neck (ap−10.7xDC) METRIC DF4XL DC1−12 1.5xDC 2.5−10.7xDC 4 I255 30° I DC<3 DC≥3 Radius End Mills Long neck (ap−30xDC) METRIC DFPSRB DC 1.3 3.3 20.5−12−1.5xDC−30xDC4 I268 30° DC≤1.5 DC≥2 Ball Nose End Mills Short / Medium (ap−5xDC) METRIC DF2MB RE3−6 4.6−5xDC − 2 I258 30° I021