small hole blues

[Thee Dragracer1951]

I have some pretty high dollar parts made of 15/5 H/T'd to about Rc48 or so.

I need to drill a .047 dia through. Depth of cut is .45 and there is a cross hole that this dia crosses. That cross hole is .063 dia

I have tried speeds from 2krpm at 1.0 ipm to 6.5krpm at 2.5ipm

I get a couple parts then the HSS drill dies scrapping the part

Machineries says 20 to 55 sfm.

I've been pecking from .02 to .07. I'm a little afraid to just drill it but wha tthe heck...what I'm doing ain't working!

[Hardmill]

48rc isnt that hard, but I would use carbide.

 

 

PEACE

[?Mark]

35sfm at the most...S2873 F0.8 or slower for hss.

Also spot drill and almost zero runout is critical.

 

Thats almost 10 x dia depth so you might want to consider using couple of drills (stub and long...)

 

hth

[JG]

quote:

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there is a cross hole that this dia crosses

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can you go from both sides?

[DavidB]

Titex carbide through tool coolant A6588TML at 7900 RPM 80mm/min no peck.

 

http://www.titex.com/

 

I've done lots of 15-5PH HT to 1025 condition and these drills rock

[Lars Christensen]

Would you be better of holepoping the holes?

[Thee Dragracer1951]

Just got rid of the pecks. 2140rpm at .5ipm

Drill went four parts.

I have a fourth axis comming for my new mill next week...I have an indexer I could use now and go from each side...

I hace some carbide coming in the morning. Time to think on it.

[LansB]

What are you using for coolant? We run .032" drills on 14-4 ht quite often. When we drill it we turn our coolant off and soak the drill with WD-40. Run out is definately the most important issue to address though.

[Rick Henrickson 65]

you should get some mitsubishi mzs and mze drills ASI or Bailey I think