Nerdlinger
Stainless
- Joined
- Aug 10, 2013
- Location
- Chicago, IL
Just drilling on-center in a lathe. I burned up two 13/32" HSS drills going 1/2" deep in 1144 "stress proof" with Blaser Swiss Lube Oil flood. I started with my usual 80SFM @ F.005 but after 200 holes the outside of the lips burned up...the tip of the drill and half way up the lips looked good as new. I thought maybe the coolant wasn't getting in there so I switched to G83 peck cycle but to no avail...the same failure mode after the same number of holes.
Then I remembered that the 1144 was a bit harder than the stuff I usually work with and saw the recommended speed is more like 60SFM at about the same feed rate (~F.005,6,7...)
SO this is my question - seeing as how the outside of the drill was black/burned and the core was good I DO believe that 80SFM was just too fast and tomorrow I will slow it down and see what happens, but still can I get 500+ holes out of a regular HSS drill in 1144 or do I need to switch to carbide??
Thank you!
Then I remembered that the 1144 was a bit harder than the stuff I usually work with and saw the recommended speed is more like 60SFM at about the same feed rate (~F.005,6,7...)
SO this is my question - seeing as how the outside of the drill was black/burned and the core was good I DO believe that 80SFM was just too fast and tomorrow I will slow it down and see what happens, but still can I get 500+ holes out of a regular HSS drill in 1144 or do I need to switch to carbide??
Thank you!