Drilling Large Holes in Stainless Steel the Easy Way 

Hi, I have a few points to make about your video that might be off help to other viewers. I trained in stainless steel fabrication and worked manfacturing high pressure vessels for companys such as Coca Cola and Pfizer so I have plenty of experience in drilling holes. Firstly , the hole saws that you used initially were commonly used in our company for holes up to 120mm diameter. The proper way to use them is to use plenty of cutting fluid or coolant and to pulse the power on and off on the drill as you use it so the drill never builds up speed or overheats. Secondly, the way you used that taper bit will burn it out in just a few holes. Don't keep the power on full when you are drilling and if you see smoke then stop as you are burning the bit. You can see from the first holes that iyt overheated as the edges are sinking down which is metal warping from it getting too hot. You need constant cooling and slow speed for stainless steel or you are wasting your time. If you redden the steel while drilling then it will become to hard and you'll just destroy drill bit after drill bit. if you use proper drilling technique you would have a 22mm hole drilled in 20 seconds. the tool is just rubbing off the steel, it needs to be slow so it can cut.

Less speed, more feed. The number 1 rule when cutting stainless is slow the rpm and increase the bit pressure. High speed and taking it "easy" hardens the metal and make the job much much harder.

Watching your video was the smartest thing I did all year.

Exactly the issue I just had and here is the answer. Several years old but absolutely timeless in usefulness. Thank you for the help!

Excellent video and comments. I'm going to cut into my stainless steel sink with my step bit tomorrow!

Thank you. The internet is an amazing resource thanks to people like you.

Thank you so much for posting! I'm trying to install glass rinser in my sink and I had no idea where to start for drilling! And thank you to everyone in the comments, all the tips and tricks really help. I'm going to start it tomorrow. We'll see how I go!

I just drilled a third hole through a very thick 3/16" (5mm) Kraus stainless steel sink. I used a tungsten carbide tipped hole saw in a 12v Bosch drill/driver. Used water for cooling. Took a little effort but it drilled out cleanly. To remove any burrs I used an 8" half round 'basterd cut' (fine) file. Thought I was going to have to go over it with sandpaper, but it's smooth enough. I used a 1-3/8" (35mm) hole saw. Hope this helps. It answers the questions I had and it worked well.

Great video. Thanks for taking the time to put this together for everyone. It takes a certain amount of confidence to put something like this out here knowing someone is totally gonna point out where you went wrong. I learned a lot. Thank you.

Thanks for posting this and even for the people commenting on how to do it better. This is how we all learn.

Thanks Steven I said a prayer to St Joseph and found your video which helped widen a hole on my stainless steel door handle thanks again

Thanks for the video and Thanks to all the helpful comments it really helps CHEERS AND GOD BLESS👍👏👏

Thanks Steve. Drilling a sink for one of my customers and had no idea how to do it. Your video helped me out. Thanks!

Yeah, I did the same thing. Started with a bimedal. Thanks for the tip.

Thank you. Your video saved me a big headache. Appreciate your posting. It was easy.

I had great success with a Milwaukee cobalt "Hard Metal, Quad Edge Tip, Red Helix" 1/4 drill bit 48-89-2313. With a little WD40 and low RPM it ripped through the stainless steel in a few seconds where a normal split titanium coated split point drill wouldn't get started. Then a Milwaukee 48-89-9201 "Jam-Free" step drill popped right through to give me a 1/2" hole, which is all I needed.

had a similar project. I gave up on drill bits and used old greenlee chassis punches. worked quickly and way better than drill bits.

Good video, just done exactly the same thing and experienced the same things . Well done for putting this up . I found a slower speed on the drill helped. But as the hole got bigger it took longer 😊

Thanks, you've done a helpful public service posting this video. The step drill is an excellent choice. One thing to note about cutting stainless steel: It work hardens very quickly. What this means is that if you take light cuts with too little pressure, the metal hardens from the heat caused by the friction of the tool. It's probably the reason the first hole was more difficult than those following, since the hole saw had very likely hardened the steel. It might be more effective to skip the oil and take a slightly heavier cut with the step drill.

Thank you very much for posting this! It seemed as though everyone said I couldn't drill my sink. Too hard to do and to tough a material they said. I figured it had to be possible as they come with holes that had to be cut out somehow as stainless isn't molded so much as bent as far as I know. seeing this vid I now know what tools I need so I can FINALLY have enough holes for a sprayer and an instant hot water side faucet! Again, thank you this is a time and money saver now that I dont have to buy a new sink!

Thanks for taking the time to make this video. It was informative. I would add that my installation instructions recommended adding silicon sealant to the bottom of the escutcheon plate gasket. Something to consider. Cheers

Thank you, much help! Getting ready to do same thing

Thank you! No doubt you saved me a ton of frustration and cussing! I'm replacing vintage pinball machine flipper buttons with modern ones and I have to make the hole larger in some stainless. Bravo!!

Awesome video. Simple. Well explained. And a time saver for me. Thanks for posting! And also a shout out for Adrian Connolly for the extra tip! What a great thread.

Awesome, thanks for showing us 👏

This was helpful. Thanks for sharing!

Great video thanks for taking the time to make it! I’m going to install a new water purifier and need to put on a new hole for the water dispenser.

Exactly what I needed to increase size of a hole in some stainless steel. Off to get a titanium step bit. Thank you so much, extremely informative. Good video.

I have the same exact job to do and this helped me thank you

Steve: this is awesome. Let me go out and buy a step drill. thanks for this awesome video

8 years later this is very helpful thanks

great recommendation on the drill bit and oil. However, the faucet takes up so much of the small sinks access by hovering over it. One would have to take out the faucet when putting a large type pan in the sink. Thanks

There's an interesting aspect about step drill bits that I learned from Adam Savage. If you are ever off center with the hole you're drilling, you can apply gentle lateral pressure to start "cutting" sideways. This way you can begin recentering the hole before it's too late!

Thanks, this and the comments below really helped!

Thank you Steven! I had exactly the same problem, starting off with the same bi-metal bit, going for a 1 1/4 inch hole for a flexible sprayer attachment that turned out to be not optional in the faucet I was installing for a friend. We left the sprayer under the sink and the same unsightly ragged hole and gouging you show. I'm headed out to get the step bit. Thanks!

This is the best video on this subject that I have found. Bravo!

You have a good quality voice sir.

Thanks for sharing

I believe the main problem he had was that there was already a center hole that was larger than the drill bit. This caused the hole saw to not stay in 1 groove. You can see this in the video by the wide ring of scraped metal. One solution in this situation is to put a block of wood under the existing hole. This will let the drill bit stay centered through the entire cut. There are machinists in this thread saying this type of bit should work fine. They are also saying that overheating was the main problem. I think that it was centering and not hear that was the main problem with the original cut. Good luck!

I was going to use a hole saw. glad I watched this first! I will be buying a step bit tomorrow! thanks for the video

Yes, a timely help for what I need. Thank you.

this helped me - i had just about given up until i watched how you did it -- thanks for the video!

Thank you! I have to drill a hole to put a faucet for my R. O. filter system....

Thanks! Was very helpful.

Use cutting oil not regular oil and run you uni-bit in low. I cut holes like these in about 30 seconds...if your bit is getting hot enough to smoke you are doing it wrong.

Lotta people critiquing what you did here with improvements, but hey the big thing here is that it worked, and you explained it well enough for a rookie like me. Thanks!

Thank you so much for this video. I am a woman taking care of an 84 year old mother. I do all the repairs and I had to do exactly what you're doing on this video it worked beautifully thank you thank you thank you.

Thanks for this video. VERY Helpful and Informative.

I love the way you talk

Thanks to this video I saw yesterday while I was at Lowe’s, I found one and bought it to use on my sink for the sprayer. Worked like a charm!

Tank you Steve, next time it wont take 20 minutes with another type of drill bit that I used. Ordering the reamer and the oil now.

I have a cheapo step bit, I did not know Bosh made one, I will most definitely get one. and great tip on using the Dremil tool Thanks for the tip !

Thanks for sharing this video as well as your experience! I REALLY appreciate it.

Thanks for the video. Didn't know about the step drill bit. Leaving to buy one now.

I just drilled a hole in stainless sink with diamond hole saw and finished sharp edges with grind stone bit. Cool diamond bit with water and don't go full thrust! I don't know why i searched it post factum but here is my advice.

Thanks for the vid - might buy a graduated step -drill bit rather than a hole bit now. Cheers

Drill a small hole and use a Greenly punch. Run it down with an impact driver. Nice clean hole.

Thanks for the reply - I'm going to se if I can work out the flat side into a hole with my dremel

Thanks for doing this video, I was having the same problem now I know what I will do :) Thanks also to those who left comments about going slower with more pressure. I have two dozen units to replace so I will need that bit to last a while :p

Thanks for posting this! This helped us a lot! 👍

If you have to do something like this again, try renting a hydraulic knockout punch from home depot or something. It takes a matter of seconds with one of those and it's a hand operated tool that you just pump with a lever. It's no bigger than a bicycle pump. Also, you won't risk warping or discoloring the material you're trying to make a hole in.

Thank you sir,appreciated

Thanks

Great video and thank you for sharing. Know how is invaluable to me. That's how much I appreciate useful and quality tutorials like yours. Keep it up!

Thanks! I'm trying to add a RO water spout. Hopefully I don't screw this up or new sink time I guess lol.

Stainless steel work hardens quickly so: 1) Always maintain force on the drill bit. 2) Keep drill RPM as low as possible, best around 500RPM which is tricky except with a cordless.

I was told by an old machinist stainless is cut or drilled "slow and hard" with good bits. I made a brake rotor for my motorcycle from a plate of stainless .4 thick. It was a bitch!

I remember the time when I drilled a hole onto my stainless knife. I just put oil on it as i drill, in full rpm! It smoked a lot! The stainless handle (where I was drilling) turned red and the wood where is was sitting turned black as it catches heat from the knife handle. I didn't know that I was supposed to go slow, but I managed to make the hole. Now I am thinking, did I destroyed my bit in the process? It was still in "one piece" though. Next time, I know what to do with stainless steel.

It all looks so easy, however I believe was not strong enough, for any women watching this, my recommendation is have someone strong do it if you are not, I accomplished one hole after 2.5 hrs. I stopped regularly and used the lubricant. The drill got very hot, and my nerves were a bit frazzled half way through as the drill would be hard to control. I finished the 35 mm hole, and smoothed the edges with dremel tool. The step drill was getting worn close to 1", and then just before 1 3/8". I would stop for 15 min to let the drill cool. Job done, I will not personally do again.

Thnak you

Oh that bit on good now boy

Thanks Steve...you've just made my job a whole lot easier!

Thank you Steve. This was a well done video. This is my next task to do.

Water would work better. Take a water bottle. Punch a little hole on the side so the water comes out like a little spray stream. Point it on the contact between the drill bit and the metal. It will keep them cool, some metal dusts will get mixed in and improves the friction/grinding. While taking them away when they are too expensive. Just like when cutting stones and tiles.

👏👏👏 Thanks Sir!

That’s, now I can enlarge the hole in my sink, big help

Awesome! thanks - just what I was looking for but didn't know it existed. Big help!

You want to go slower with that bit. If you get the stainless hot, you'll work harden it and it'll be much tougher.

Thanks very good infomation

Sink stainless is a hard metal. Of course a bi-metal hole saw would have trouble and micro dull immediately. You need a carbide tipped hole saw. Your cutting tool needs to be significantly harder than the material you are cutting. This is cutting 101.

You can use tungsten carbide hole saw

Yw my pleasure

That Faucet tho... :O WOW!

Carbide tipped hole saws also work much better than the bi-metal for stainless and very hard metals. Milwaukee makes them and so do many other companies. I had a similar experience with the bi-metal and the carbide went right through it.

wonderful video! I wish I had known this all my life! It would have saved an awful lot of profanity : )

Thank you very much for your useful video

You sir, have my one like.

This old stainless steel sink was very thick and I didn't want to take all day to do the job. You can increase the rpm's with a little oil and it goes very quick and smoothly.

AWESOME, thanks for posting.

The step bit should do the job. I was trying to figure out how to install a better faucet without ripping out and redoing the entire counter!

I have a 1.25” faucet hole in my stainless steel sink top. The back of the hole is flat- I want to replace the faucet but the faucet bolt of course is also flat on the backside - the only replacement faucet I can find is a complete circle without the flat back on the holding bolt. What can I use to carefully complete the circle on the hole so I can install a new faucet with a circular bolt?

Thanks for the video. I'll have to get one of those bits. I was trying it with the bi-metal hole driller and not getting anywhere.

Thanks for this video- I was just wondering how I was going to put an extra hole for an accessory item without replacing the entire sink!

Thank you :)

Thanks Steve, I will try it today!!!

Thanks for the instructive input!

That's great how about a 5 inch hole without a plasma cutter?

I saw carbide tipped hole saws yesterday, made by Klein. Pricey too. Perhaps you could buy the tool you need then resell on eBay. I can imagine there are a lot of people in your shies who will be looking to buy used, at a discount because the only need to use them once.

Whenever working with Stainless, keep your speed LOW! Holesaws work great if you use a variable seed drill motor, and let off the trigger if you go above 200-300 rpm. Cutting oil or tallow are also very important.

Don't forget to cover the drain with a dish towel or something.