Drilling Thin 304 Stainless

[scratchedup]

I installed SS side panels to my new refrigerator. When finished there was a tab with a small screw hole with no reciprocal receiver hole (One on each L/R side) and no mention in the instructions.

Seems my cabinet install guys inadvertently bent the tab upward.

I would like to run a #8 sheet metal screw to hold it down but the stainless is VERY hard to drill and a backer while drilling is problematic.

Any ideas? I believe its 304 stainless...not not magnetic.

THX

 

[zmotorsports]

When enlarging/drilling any thinner materials regardless of stainless steel or carbon steel I prefer to use step drills (Unibit) as they don't grab and shear the metal and they produce a nice chamfer. You may have to remove some fasteners to back the ear away from the substrate material however.

If I have a virgin hole I need to drill in thin sheet metal I prefer to use my sheet metal drill bits as they cut on the outer diameter of the hole and don't shear or cut a triangular profile in the material like a standard drill bit.

 

[RTM]

I'd clamp the pieces together while drilling, (the two bottom ones) to get a little more rigidity. You can also clamp a sacrificial piece of wood underneath. both pieces clamped to the wood will make it easier, longer will allow more clamps down the length to get more rigidity.

I've had good luck with a step bit on SS when I don't have a backer

 

[The Cobbler]

I ask if it's actually required, or are you just creating unnecessary work for yourself ? I assume there's another panel that goes overtop of every thing?

 

[scratchedup]

there is no other panel...

The hole only needs to be say 11/64" or so ...I do not think step drill bits go this small

 

[PCustoms]

Looks like that is meant to screw to the upper cabinet to prevent tipping....

 

[The Cobbler]

I'm wonderinf if those tabs were meant to slip underneath and not be exposed. in any event the whole thing seems odd that there's not a finished top pc.

 

[fastev]

Another vote for a step drill.
But, if you want to use a conventional bit, cobalt is the way to go. Just be forewarned that the exit of the hole will be ugly.

in this situation I’d honestly either forget about it or get a few self drilling screws and swear a bunch until one does it’s thing.

 

[speed bump]

Start with a new 1/16 drill bit then send a stainless sheet metal screw through it. Dont let it get hot.

 

[mechcsu]

For stainless steel you want a larger included angle on your drill bit especially when trying to open up holes. Without breaking the bank for one bit I would suggest a cobalt 135 degree. Larger included angles are available and will leave a cleaner exit hole but they get pricey.

 

[d.mcfarland]

What about just cutting it off?

 

[tarbellb]

Do you need the tab, if not cut it off (dremel?)

Want to keep it, grab a C clamp vise grip, pinch together, redrill with the appropriate size bit or start with pilot bit and use step drill bit.

Important:
lots of pressure
good new bit
use the shortest bit possible to avoid damage

 

[Indexmill]

"If I have a virgin hole I need to drill in thin sheet metal I prefer to use my sheet metal drill bits as they cut on the outer diameter of the hole and don't shear or cut a triangular profile in the material like a standard drill bit."

What the hell is a "sheet metal" drill bit? Of course, I understand what the words say; but, I have never seen one. Can you share?

 

[zmotorsports]

"If I have a virgin hole I need to drill in thin sheet metal I prefer to use my sheet metal drill bits as they cut on the outer diameter of the hole and don't shear or cut a triangular profile in the material like a standard drill bit."

What the hell is a "sheet metal" drill bit? Of course, I understand what the words say; but, I have never seen one. Can you share?

Sure, here is a picture of my Lawson sheet metal drill bit set that I posted on my Projects 2.0 thread a couple of years ago when I was drilling a hole in a transmission pan. You can see in the picture that they lock into a center punch hole and then the outermost edge does the cutting to drill a perfectly round hole that doesn't grab and tear the metal when it goes through. I have also taken standard drill bits and flattened them off to nearly flat for use in a similar manner but only in a pinch and as needed.

 

[jpaw]

Looks like that is meant to screw to the upper cabinet to prevent tipping....

I agree.
But if it's not necessary and in the way I would probably cut it off.

 

[Bondo]

Ayuh,..... What I've found when drillin' stainless is, you need to start with a nice sharp drill bit, 'n don't stop or hesitate when drillin',.....
Stainless steel work hardens very quickly, so when it starts to drill, Go with it,....
If ya started with a dull bit, yer probably not goin' to be able to drill out that same spot,....

 

[PBCampbell]

@zmotorsports---You have a part number for those drills? They look like brad points and I can't find any reference to "sheet metal Drills" on Lawsons web site.

 

[Rinspeed]

I've drilled thousands of holes in SS and believe you are over-thinking it just a little. New bit, little oil and low RPMs, center punch helps a lot to keep the bit from walking. Starrett makes a hell of a snap punch but they are a little pricey.

 

[Grant Gunderson]

Sure, here is a picture of my Lawson sheet metal drill bit set that I posted on my Projects 2.0 thread a couple of years ago when I was drilling a hole in a transmission pan. You can see in the picture that they lock into a center punch hole and then the outermost edge does the cutting to drill a perfectly round hole that doesn't grab and tear the metal when it goes through. I have also taken standard drill bits and flattened them off to nearly flat for use in a similar manner but only in a pinch and as needed.

How are those different than spot weld drills?

 

[zmotorsports]

@zmotorsports---You have a part number for those drills? They look like brad points and I can't find any reference to "sheet metal Drills" on Lawsons web site.

Sorry it took me a bit to get back with you. I had forgotten to take pictures of the bits and get a part # last week.

Here are some better pictures along with the Lawson part number, Lawson labeled these as Crown Point drill bits. Not sure if it is still viable as I purchased these probably more than 20 years ago.









Hope that information is helpful.

 

[PBCampbell]

Ayup, discontinued, lol. Thanks for the effort though.

 

[zmotorsports]

Ayup, discontinued, lol. Thanks for the effort though.

That *****. Must not have been big sellers. Too bad too, because I really like them and have actually used them a lot over the years as they make nice perfectly round holes in sheet metal unlike a standard drill bit.

 

[CGarage]

Make sure you verify and read THE MANUAL before drilling holes and cutting things that might not need to be cut or drilled.

 

[Samuel Load]

It is better to drill a round hole with a step drill bit. Cobalt is the best.The bottom right corner of the picture is the hole I drilled in 5mm thick stainless steel