Need Help!- SS 316L machining tips??

[kevh]

HI Guys

Have got two components to make outta 316L on my Haas TM1 , fairly simple milling apart from 12 x 1mm dia holes 8mm deep.(normally cut toolsteel/mild steels)

Any pointers to speeds and feeds(metric if poss) ,coolant with tip tools or solid? 1mm drills , peck ammount ? etc.

Any help at all would be greatly appreciated.


Cheers Kev

[DSL PWR]

I think you are screwed, unless you have a coolant inducer. If you peck drill you will work harden the stainless, and then it is all over. For speeds and feeds start at about half of mild steel.

[kevh]

Thanks for quick reply and being so honest DSL

Im goin to have a go i think ,as i have a backup plan . Edm machines, normal and fast hole machines which are good for blastin out broken tools.

Just wanted to try and do it the quicker, traditional way

For general milling of SS, do tip cutters need coolant ??

Thanks for help

Cheers Kev

[epmtool]

http://www.harveytool.com/products/p...niature+Drills

These drills might work alright for you if you have plenty of coolant presure.

If these parts are not production, you might be better off drilling the holes manually with HSS and a whole bunch of cutting oil.

As far as milling, just use airblast.

[kevh]

Thanks for reply epmtool
( amazin lookin drill how the heck do they get coolant holes thru a 1mm carbide drill!!??)

No thru coolant im afraid , will try Hss and oil , any idea for speeds and feeds and ammount to peck?

Cheers Kev

[epmtool]

I would try 1600 rpm and a feed of 2 ipm

Are you still doing this on a VMC or a manual machine?

Once that drill starts to dull you will work harden it and it will be over...

If you are CNC'n it i would recommend programming maybe 2 or 3 drills going

.1 deep with each one with a peck of .032.

[SherlineGuy]

KevH
Please let us know how this job turns out! We make almost everything out of SST, and I do specify a 1mm hole, but at only about 1/2 that depth. I know that he has to get those drills that are made in Germany...Guhring I believe, and no-thru coolant either.

[stevo1]

We use to run a ton of 316L material. I never had to drill that small of a hole before in this material. The big question….is it the Ezdrill 316L? We ran into an issue were the supplier sent us the wrong material and we broke every drill and chip every turning insert when machining. We knew immediately that it was the material because we had run 1000’s of these parts for over 10yrs with no problems.

Anyway we used solid carbide drills and also found that cobalt worked very well. We never had thru the spindle coolant. I would run 30sf with a .004-.008 chip. I would run about .03-.05” peck.

Stevo

[kevh]

Hi Guys

Thanks for all the replies

Finally completed the job , which i think will serve the purpose.

Blockin the job up , go thru my taegutec tip pretty quick as i was only had coolant option which i think caused thermal crackin , but might try and set up an airblast if i get more to do , and if running dry you need a minimum high surface cutting speed to get rid of the sticky chips!!

The 1mm holes were pretty twitchy to say the least , but went slow and steady, with a cleveland split point hss tin coated drill.

3000rpm 25mm/min with 0.3mm peck and a drop of oil on the drill to go with the coolant now and again.(when it started sounding really rough!!)

Did all the holes in stages of 1.5mm deep incase of breakage. (that never happened )


It was great doing the last stage the T piece back on the wire edm!!

Here is a pic or two

Cheers Kev

[John Welden]

Whoever said not to peck drill is crazy. The material won't work harden with the proper speeds and feeds.

Surface Speed 35.

For you 1mm drill run about 3500 rpm, feed rate 2.2 ipm chip load should be around .0003
You'll have to convert those to metric.

Peck .010 if you're not in a hurry

Run coolant.

We use Guhring brand drills with tialn coating.

It's really no big deal, you shouldn't have a problem.

[Geof]

Originally Posted by John Welden Whoever said not to peck drill is crazy. The material won't work harden with the proper speeds and feeds.....

Where do you get this idea? 316 will work harden whetever your speed or feed is. Just bending it will work harden it.

[John Welden]

Originally Posted by Geof Where do you get this idea? 316 will work harden whetever your speed or feed is. Just bending it will work harden it.

Ok so you're going to cram a 1mm drill 8mm deep without pecking? How do you suppose deep holes are drilled?

I've drilled 1000's of holes in 316 with pecking. I guess mine didn't work harden.