Need Help!- DRILLING 17-4 Stainless Steel

[Ed MacPherson]

Hello,
I have to drill some .094 Dia. holes thru 3/8" 17-4 S.S.
Material will not be Heat Treated.
Question is for recomendations of Drill Bit Mat./ Style , Spd. Fd. , Pecking etc.
Would be run on a HAAS VF - 3 - Coolant available if proper way ? 10,000 RPM Capability.
Thank You,
Ed

[DMF_TomB]

"I have to drill some .094 Dia. holes thru 3/8" 17-4 S.S.
Material will not be Heat Treated.
Question is for recomendations of Drill Bit Mat./ Style , Spd. Fd. , Pecking etc."
.
if it were me i would try a manual drill press and experiment with different speeds and try to estimate reasonable feed rate and pecking rates and coolant
.
suggestions from books and others are helpful but you can learn much from doing some experimenting.
.
also screw machine drill bits are shorter than jobber length and most times work better and i find break less.

[Delw]

Ed.
I used Precision twist drill 135degree split points in stub length.#43 drill size I think I had to run 1.30 deep
I found that if I rand 75% to 50% of what the drill manufacture reccomended it worked 10x better with no broken or worn drills.
Just looked at my program for a #43 (.089)drill dia I ran 1000 rpms at F1.0 30 holes were .485 deep 5 holes were .992 deep I used a peck cycle of .1
Ran on my vf2ss.
the notes I have on the program are drop spindle speed 10%, and use HiRoc carbide next time.

because its not heat treated the material will be gummy, and small drills have a tendacy to break on 17-4 when breaking through. I would make sure you check the drill every few holes.

Fake edit: Also ran flood coolant
Delw

[Ed MacPherson]

Thank You folks for replies.
I have done some further research also - and will be trying a M.A. Ford Drill.
Carbide , 140 Degree w/ 30 Degree Helix.
Fact. Recomendation is SFM 95 I.P.R. .002 .. I'm going to go with 1x Dia pecks as well, & Flood coolant.
I'll post final results , drill series and part # when done , providing it worked well.
Screw Machine Drills per Tom B'S comment below do work well also I agree, and have used them in many cases where you may not be told to use this type of drill at first.
Thanks again All,
Ed

[Delw]

Ed with carbide I wouldnt peck drill with a canned cycle unless you feed in real slow after every peck, it will chip the drill if there is any chips in the area.
I usually write the code by hand for this instead of using a canned cycle

Delw

[Waynno]

#43 (.089)drill dia I ran 1000 rpms at F1.0 30 holes were .485 deep

I just drilled some lockwire holes in some 17-4 parts, Good quality cobalt drills
nearly the same feed and speed and no breakage. I agree 100% , no carbide,
the chips will destroy the drill before you get though one hole

[CLATHAM]

we use 17-4 about 75% of the time. we only use carbide drills. depending on the size of the hole to how deep. for little holes we use nachi drill. for deep hole we use walter or mitsubishi drill. have drill .250 dia hole 8.0 deep in 17-4 just one shot using thru spindle coolant. using feed and speed from there books

[Shane123]

i agree with the mitsubishi carbide coolant-thru drills, they seem to take every thing i throw at em..... 303, 304, 316L, 304 plate (uggg)........