Ok, I need some input on this. I need to add 4 holes 1/16" diameter in 304 Stainless Steel. I will be drilling about 1/2" deep and breaking out into a radius. Anyone have any ideas?
Start on the flat side. Spot drill. Use sharp drill. Use cutting fluid. Not a big deal otherwise.
Using white vinegar on stainless, especially 316 makes drilling a cinch. I don't know why or even who told me but I have used vinegar and it really does work well.
peck drill and make sure you clear the chips try an acid brush in one hand and the handle in the other maybe a little dish of cutting fluid to dip and apply coolant.
drilled about 40 316 and 40 304 bolts the other day, with 1/8" bits.
had to resharpen the bit every 12-15 holes. all we had was sulfur oil, so it was used.
no biggie, just paying attention to the bit and keeping it sharp worked well.
1/16" bit would mean I'd go find some bacon grease or something heavy and fatty.
i'm prolly wrong again with what to use , but my bible is at work...
There's nothing too special about 304. I machine 316L all day. Not much different. I usually drill 60 sfm. On a 1/16 drill, I'd probably peck drill it with a .0005" to .0007" feed. We've had every coolant under the sun where I work. Currently using a Castrol vegetable oil based coolant.
Don't ever let the drill dwell or rub (makes 304 workharden instantly), make sure it's always either feeding forwards at the rate that produces a proper chip, or retracting.
I bet you already knew that...
But there are some subtleties that don't get mentioned so often:
The critical moment is the first contact, needs to be positive, not tentative.
Also centerpunching is best avoided. (Spot drill, as Randy suggests)
If you do ever need to centerpunch materials prone to workhardening, it's a good idea to grind four facets (like a pyramid) on the tip of the punch, so the action is a combination of cleaving and displacement, and the first contact of the drill is with the least displaced (hence softest) material.
Very good pointers!! I will remember this for future reference.--Thanks!, Grant