Switched from HSS to carbide end mills after 8 years of stubbornness

For the longest time I refused to use carbide end mills on my Bridgeport. Thought they were overpriced and brittle. Then about 3 months ago I had to finish a run of 304 stainless steel brackets for a customer in Cleveland. My HSS tools were burning up every 20 parts. Finally gave in and bought a pack of 4 flute carbide end mills from a guy at a trade show. I got 150 parts out of one tool before it started sounding different. Never going back. Anyone else hold out on switching to a better tool for way too long?

2 comments

2 Comments

theabarnes1mo ago

Tried that on some 1018 steel and snapped three bits before I got the speed dialed in.

young.spencer1mo ago

not to be that guy but you probably could have gotten even more parts if you tweaked your feeds and speeds a little. carbide is great but it really needs the right rpm and chipload to not chip out. on a Bridgeport you're usually stuck around 4000 rpm max so you gotta bump up the feed rate to keep the tool from rubbing instead of cutting. I usually run around 0.002" per tooth on 304 and it makes a big difference in tool life.