Drilling 0.3 mm holes into 0.3 mm stainless 1.4301 sheet metal

[Thorsten Steinberg]

Hello,
I'm about to drill a bunch of holes into this metal foil with carbide drill(s) on my CNC mill. Does anybody have hints on how to go about it successfully? I'll probably have to glue it or fasten it somehow else to another piece of material to avoid instant breakage of the drill while passing the bottom surface. Any assistance is welcome. From HSM I get 19000 rpm and 50 mm/min feedrate.
Best regards
Thorsten

 

[minh-thanh]

I would stick a piece of aluminum or brass underneath, 502 glue is fine if the surface is clean enough.

 

[Toymaker]

If the area isn't too large, sandwich the metal foil between two sheets of polycarbonate. Drill though the top sheet into the foil and then slightly into the bottom sheet. Clear polycarbonate allows you see what your progress.

 

[djc]

If the area isn't too large, sandwich the metal foil between two sheets of polycarbonate.

The visual aspect is appealing but polycarbonate will have such vastly different cutting characteristics to stainless that its use might have greater disbenefits.

In particular, what would be the thickness of the top sheet? That would put some limits on the minimum length of the drill bit. If the PC is the same thickness as the stainless, the time per hole is doubled (assuming constant feed rate). Even at equal thickness, the stainless swarf has to travel twice as far to escape.

The area of the piece being drilled (or the furthest distance of a hole from a clamping point of the top slice of bread) will influence the thickness chosen. It has to be stiff enough not to flex upwards when the drill is withdrawn.

 

[ChazzC]

Punch instead of drill? Would leave a cleaner edge, whatever method you try with drilling will risk grabbing and having to start over.

 

[krypto]

Punch instead of drill? Would leave a cleaner edge, whatever method you try with drilling will risk grabbing and having to start over.

Ok, I'll bite. Show me how to make a 0.3mm punch! At least 0.3mm carbide drills are relatively cheap and easy to find.

I've drilled a few 0.3mm holes in 3D printer nozzles with the Dumore drill press which went without drama, but they were brass. Can't say I've drilled stainless shim stock before.

 

[Toymaker]

The visual aspect is appealing but polycarbonate will have such vastly different cutting characteristics to stainless that its use might have greater disbenefits.

In particular, what would be the thickness of the top sheet? That would put some limits on the minimum length of the drill bit. If the PC is the same thickness as the stainless, the time per hole is doubled (assuming constant feed rate). Even at equal thickness, the stainless swarf has to travel twice as far to escape.

The area of the piece being drilled (or the furthest distance of a hole from a clamping point of the top slice of bread) will influence the thickness chosen. It has to be stiff enough not to flex upwards when the drill is withdrawn.

The sandwich method is what I used to drill holes and mill slots through 0.010" (0.26mm) thick stainless sheet to make the reed valves in the photo below. All discs are 3.3" diameter and were clamped onto the mill table through the center hole. I used 3mm thick polycarbonate sheet top and bottom as the sandwich material. The top-right reed valve disc, seen in the photo below, is pinned to an aluminum disc behind it. The lower-left reed valve disc is lying against a much thicker aluminum disc.

Since Steinberg's stainless sheet is only 0.3mm thick, the amount of swarf needed to be discarded by the drill will be minimal and shouldn't be a problem. And, since he's using a CNC mill, feed rates can easily be faster through the PolyC,... then much slower through the stainless. Just insure the top PolyC is thick enough to provide adequate stiffness to prevent the PolyC from lifting during drilling.

 

[ChazzC]

Ok, I'll bite. Show me how to make a 0.3mm punch! At least 0.3mm carbide drills are relatively cheap and easy to find.

I've drilled a few 0.3mm holes in 3D printer nozzles with the Dumore drill press which went without drama, but they were brass. Can't say I've drilled stainless shim stock before.

1) buy a die-set from a company that specializes in them (remember to get spare punches).

2) Buy the necessary tools to make yourself (more money, but you’ll have the machines & tooling moving forward).

Either way, build the costs into the job pricing.

While writing this I thought of another method: EDM (plunge not wire, obviously). With the thin material you’re working with you could maybe build a DIY setup?

 

[bluejets]

From HSM I get 19000 rpm and 50 mm/min feedrate.

My experience with drilling speed for stainless is keep the speed low and the pressure on.
If 19000 is what you expect to use, I'd say be prepared for mass failure as it'll simply burn the tip clean off.

 

[phred]

depending on the application, have you thought about a laser engraver, fairly cheap and a 10w diode laser should punch a hole in shim stainless.

 

[Thorsten Steinberg]

My experience with drilling speed for stainless is keep the speed low and the pressure on.
If 19000 is what you expect to use, I'd say be prepared for mass failure as it'll simply burn the tip clean off.

HSMAdvisor says 19000 rpm for a TiAlN coated drill, 11000 for a none coated