Drilling 17-4 without coolent

[CAM CRAZY]

Hello,

I am trying to drill a .0937 hole in 17-4 in a high speed machining mill. I don't have flood coolent, only mist. I am going through drills like crazy. Cobalt, carbide. it doesn't matter. Cobalt I was running at 20 SFM and the carbide I tried 80 SFM and 40 SFM. Does anyone have any recomendations for speeds or cutter brands?

 

Thanks

[chris m]

I'm not sure about no coolant, but we use Guhring 6400 series carbide in 17-4 with great success. I am not sure that this series goes down that small, but we have a 2.55mm so it might. We also use Guhring HSCO parabolic drills in 17-4; used to be F5522 but I think they've since changed the nomenclature to a new designation.

 

Good luck

 

C

[workmantm]

Try the Accupro drills from MSC. The 4X series of drills have been running great for me at a very low cost. I don't know if the lack of flood will hurt you, but depending on the hardness I'm getting a ton of life from my drills. I run at 150SFM and have yet to replace a drill in a job. Average life has been 208+ inches of drill life.

[Salt4cad]

OSG Drill are the way to go, CHeck them out

[taperlength]

Feed is more important than speed. Try more feed in small increments.

 

Cheap 17-4 will eat up drills too. The good stuff has elements added for machinability.

[Fretless]

try the drill manufactures recomendatins for speed feed and peck amount

[Fretless]

try the drill manufactures recommendations for speed feed and peck amount

[Colin Gilchrist]

How many holes, and how deep? I've programmed parts before where I would peck drill down say 1/4 of the total hole depth, then programmed (with a manual entry toolpath) a dwell cycle to allow the tool to cool down. Then another 1/4 deeper, another dwell, ect.

 

17-4 is a high Chromium/Nickel steel. It can be very hard and tough, depending on how it is heat treated.

 

What hardness is it at? Has it been heat treated? Annealed?

 

Do not use HSS drills, you'll need HSCO or carbide...