drilling small holes

alpha1 · Sep 29, 2005

I encountered a problem recently in drilling small holes, drill size is #76 (0.020" diameter),
depth is 0.075", material stainless steel 316,
I used cutting oil, tried several rpm on my precision drilling machine but drills keeps breaking

, any suggestion to solve the problem

alpha1

Greenie · Sep 29, 2005

Keep the drill cool, flood cooling if possible and clear the flutes CONSTANTLY, keep pecking at the hole and be carefull while doing it.
The drill revs should be up at somewhere like 5000 RPM, that's why the coolant and pecking at the hole is required. Stainless steel 316 WILL get hot at the drill tip and self harden and the hole WILL swell and grab the drill too, double whammy when working with that stuff.
Just take your time, it is possible to do.

metal_twister · Sep 29, 2005

Go to Enco and get yourself a micro feed chuck.

For drilling tiny holes. It has a feed ring that you grab and feed the drill with just finger pressure. The best way to drill tiny holes manually.

RFERG43 · Sep 29, 2005

I use carbide p cboard drills. They have a 1/8 inch shaft with about 1/4 inch of twist.

Davis In SC · Sep 29, 2005

A Servo Drill press would be the ticket for that job... I sometimes use one of the Micro-Drill attachments, but there is a drawback to it, the length of it will allow a drill to wander. I like to centerdrill with a 000 1/8 body centerdrill, in a collet, then install the Microdrill, put the small drill in it, & start drilling... Also, it pays to be careful, not to put any side load on the Knurled collar, as you use it....
That Servo Drill press will spoil you, I really like mine... Got another one coming from Ebay , for a customer...

PBMW · Sep 29, 2005

Put it in the Haas and push the button and walk away to get a coke...

But seriously, Lots of RPM and peck. Light touch and use a lot of cutting oil.
Jim

JRIowa · Sep 29, 2005

Lots of RPM - I figure about 16,000 is right for that size of drill. If you don't have that much, run as fast as you got.

Get rid of the oil. A full synthetic is better, a little air, or WD-40. You need something light that will keep the chips out, not hold them. Keep the drill clean.

Light feed - I have the micro holder also, but mine's keyless. I also like cobalt drills for the small stuff in stainless.
JR

rivett608 · Sep 29, 2005

For sizes in that range I use Titex drills....... they have 1 mm shanks with just a little drill at the end....... and I run them in a Cameron drill press..... I have drilled thousands of holes this way......

alpha1 · Sep 29, 2005

Hi Thanks for your replies, Where do you get the titex drill?

,
alpha1

DDYTDY · Sep 29, 2005

I like Titex or Guhring. The shanks on the Gurinrig got just a little more flex so might be more forgiving in some applications.

In 316 premium drills are a must as well as plenty of coolant. Also you need a positive feed. If you just dwell on it will work harden......snap

Good luck

Ray

I think MSC has Titex, get the coated ones

JRouche · Sep 29, 2005

http://www.servoproductsco.com/specs/80856_focus-on_small_hole_drilling.pdf

JRouche

jkilroy · Sep 30, 2005

No doubt these guys know a lot more about small hole making than I. I would be hard pressed to find a bit in the shop smaller than 1/8. However I will add to the comments on work hardening. 316 works hardens if you look at it wrong.

DDYTDY is right about positive feed. That got me to thinking about drilling machines that might have a power feed that would work in this situation. That would have to be an expensive drill.

L Webb · Sep 30, 2005

Our former machinist who leases space from us dropped in yesterday to drill some .010" holes in some .100" thick 304 stainless.

He did them on his Bridgeport at a speed of 1750RPM. He snapped one carbide drill trying to feed with the quill. He then fed with the knee and did the holes fine. I felt the speed was way too low but it worked.

Les

Metal Slave · Sep 30, 2005

That's a pretty small hole you're drilling so I don't know if this will help your situation.
It seems a little strange to me that with a depth of only .075 it's giving you that many problems.But with a drill that small I would imagine after the first .020 or so the chip is already stickin to the bit.Alot of times it's easy to think that the chip is coming off the drill when you go to brush on more oil,,but more often than not,the chip is still there.It's just really hard to see because the chip is so fine.What I have found that works great is having one of those toothbrush looking SS wire brushes handy & when you come out of the hole,hit the wire brush on the tip of the drill & move it up & down the flutes.You'll usually see the chip fling off into the distance or it will stick to the brush.Then add more oil & carry on.And I would imagine after pecking .010-.015 it would be time to get out and clear the chips,,,not sure if this will help for a .020 diameter drill but for slightly bigger holes .040-.090 or so it's a lifesaver,especially with copper.

jim rozen · Sep 30, 2005

Mmmmm. Guhring.

Jim

WILLEO6709 · Sep 30, 2005

Is it a through hole? My guess is the bit breaks as it starts to break out the bottom. Try putting an expendable piece under it to drill into and setting a depth stop.

ow2knives · Oct 1, 2005

I drill a great number of small holes in Titanium, 416 Stainless and pattern welded or damascus steel. Here is a picture of a 27 thou through hole drilled in 416 stainless, 0.75 inches deep.

I used my Deckel FP1 with standard vertical head to do this . The drill was held in an Albrecht 0 - 1/16th inch chuck. Pecked at it and kept a liberal amount of WD 40 at the hole entrance whilst drilling. Revs 2280rpm. It is important to feed with enough pressure to cut and not to rub but at the same time do not feed so fast that the chip load becomes too heavy. Never drill more than the drill diameter without clearing the chips. This becomes somewhat tiresome when the hole gets deep.

Perhaps it might be mentioned here that the quill on the FP1 vertical head is not the least bit sensitive but with care a great deal can be accomplished.

Hope this helps.

OW

SND · Oct 1, 2005

One way to do it on a vertical mill that I tried a few times is to use the depth stop and quill. Crank the machine to its highest RPM. Move the depth stop say .001" down at the time and peck, peck and peck. If the depth stop is too hard to fine adjust. Lock it in place and move the table up a little bit after every peck.

alpha1 · Oct 2, 2005

Thanks for all your the reply

, I used the sensitive drill and guhring bit on the mill and it gets better

,
The problem with a lot mill head is that you can not do pecking very well

. just like shooting a mouse with a canon

...
alpha1

alpha1 · Oct 2, 2005

"sensitive drill" = microfeed chuck as posted by metal-twister...

drilling small holes

Aluminum

Aluminum

Cast Iron

Aluminum

Diamond

Titanium

Diamond

Diamond

Aluminum

Aluminum

Stainless

Diamond

Titanium

Hot Rolled

Diamond

Diamond

Cast Iron

Diamond

Aluminum

Aluminum

Similar threads