Drill bits for stainless steel sheets

[signcrafter]

I need to drill about 40 holes in some thinner stainless steel sheet. Hole size will be 1/4" or smaller. What is the best drill bit for this? I only need one size so can order a couple of them but just seeing what type I should get. Cutting oil when drilling?

 

[PelicanPines]

I would use these... you need to drill a pilot 1/8" but then these bits cut a pretty damn near PERFECT hole.

https://www.amazon.com/Blair-Equipment-11090N-Rotabroach-Cutter/dp/B000LQOCRK/ref=sr_1_5?ie=UTF8&qid=1497624580&sr=8-5&keywords=annular+cutter

 

[PelicanPines]

and YES... use a dab of oil.

 

[American Locomotive]

How thin of a sheet? Is punching an option?

 

[signcrafter]

I would use these... you need to drill a pilot 1/8" but then these bits cut a pretty damn near PERFECT hole.

https://www.amazon.com/Blair-Equipment-11090N-Rotabroach-Cutter/dp/B000LQOCRK/ref=sr_1_5?ie=UTF8&qid=1497624580&sr=8-5&keywords=annular+cutter

Hole will be less then 1/4" diameter so just need a drill bit.

How thin of a sheet? Is punching an option?

Not sure the exact size but less then 1/8" thick sheets. Punching would be an option and I do have a Whitney but the sheet is already on the wall so that rules punching out.

 

[mrjaw14]

Maybe try cobalt drill bits in the size you want plus a pilot hole bit? Stainless takes longer to drill, and wears bits out faster, but a regular bit will do it. Cobalt will have longer life. Another option would be nice HSS bits. Just not the big box **** coated bits

 

[yaidunno]

Pick up a step bit or two.

 

[royesses]

135° cobalt drill bits. Don't let the drill sit and spin without cutting. Heavy even pressure so the bit is always cutting. A good cutting oil will help.

Roy

 

[T45]

Do some homework on the substrate...if the stainless is work hardening or not you may want to use something as noted above cobalt m42 or maybe sometimes HSS m7 like norseman/champion...either usually come in a 135 degree split-point.

Also, unless you need a long-access-bit, I would opt for a machine-screw or mechanic length and skip the jobbers.

 

[larry_g]

Do some homework on the substrate...if the stainless is work hardening or not you may want to use something as noted above cobalt m42 or maybe sometimes HSS m7 like norseman/champion...either usually come in a 135 degree split-point.

Also, unless you need a long-access-bit, I would opt for a machine-screw or mechanic length and skip the jobbers.

Agree here, know the material you are working with. Some stainless machines pretty good and some is a *****. I also second the screw machine length bits. If you need a round hole then a twist drill would not be my first choice.

lg
no neat sig line

 

[leg17]

Drill press or by hand?

 

[kd3pc]

Drill press or by hand?

the piece to be drilled is on the wall...

 

[mowkep]

We use thicker goo made especially for stainless. We get it McMaster Carr. I can't recall the name off hand. Works great though. But it will oxidize regular steel if you don't clean it off right away. Sharp tooling and slow speed

 

[Marctrees]

Seems to me a good quality "step bit" would be great.

As said above, decent feed pressure, keep it cutting the whole time.

Other than the hardness, physically simple to sharpen if needed.

But, I am just an occasional metalworker, can't advise further as to lube, etc.

Marc

 

[rk_tek]

I would use a step drill myself. Easiest way to get a clean hole with it mounted.

 

[MJD1]

Use a quality brand such as Viking , cobalt bit. Anchor lube, which is a almost paste like cutting fluid works very well.

 

[monkeyspanners]

Pilot drill for hole saw, 1/4" and pretty robust.

 

[dr_clyde]

I routinely drill stainless, I work in an food production environment. Everything is stainless sheet.

Twist drills in sheet metal tend to make out of round holes. If you must use a twist drill, use Norseman/CTD drills. Their high molybdenum content makes them well suited for SS. Otherwise a good cobalt drill. Lots of feed pressure, low SFM. Use machinery's handbook for the formula for RPM to get the right SFM for your size.

However, if you need a nice round hole, Hougen makes a set of mini rotobroaches. They work excellent, just center punch and drill.

Best lube I've found is Union Butterfield, followed by Tap Magic. Avoid the dark sulphur oil on SS.

 

[lilredex]

Made a wavy flavour bar/ heat plate similar to the link, from some scrap SS that may have been a commercial kitchen top at about 16Ga, was pretty tough stuff to bend. Drilled more than 40 holes (1/2") in it with a step drill, with no pilot hole. It was an easy drilling job and the bit was nothing special, just from a pack of three from Canadian Tire ($10). Drilled them all dry too, on the DP.

https://www.amazon.ca/dp/B002DQC6VA/?tag=atomicindus04-20