Jul 19, 2016· Milling Delrin? Speeds, feeds, coolant? I have a bunch of delrin jobs coming up. Just wondering what you guys use for speeds, feeds, and coolant? I plan to use endmills designed for aluminum, and standard drills and taps. I'm programming the first job now. I'm using 1/2" and 1/4" SGS S-carb endmills.