Hi,
Been drilling with our Kenna DFT Ø47mm (approx. 2 inches diameter) drill into 316 stock today. We just weren't able to break chips, just hefty strings. We're drilling deep - 190 mm. Started off by using recommended values, but tried changing speed/feed as we went along. The problem isn't that it's not cutting, but when it doesn't break chips it packs the flute and causes trouble. Any of you guys used these DFT drills in 316? All tips are appreciated! Trying new and different inserts tomorrow. Machine is a Haas ST30Y which was seeing about 70% spindle loading. RPM was around 1000 and feed approx 0,12mm/rev.
Edit: We realize that we're going deeper than recommended here, so pecking is last resort if we can't make chips.
Been drilling with our Kenna DFT Ø47mm (approx. 2 inches diameter) drill into 316 stock today. We just weren't able to break chips, just hefty strings. We're drilling deep - 190 mm. Started off by using recommended values, but tried changing speed/feed as we went along. The problem isn't that it's not cutting, but when it doesn't break chips it packs the flute and causes trouble. Any of you guys used these DFT drills in 316? All tips are appreciated! Trying new and different inserts tomorrow. Machine is a Haas ST30Y which was seeing about 70% spindle loading. RPM was around 1000 and feed approx 0,12mm/rev.
Edit: We realize that we're going deeper than recommended here, so pecking is last resort if we can't make chips.