Drilling stainless steel worktop

[eacmen]

Recently got saber garage cabinets with stainless steel worktop. Trying to mount the vise to the worktop and having a very difficult time drilling through the stainless worktop (which I suspect is 12 ga stainless wrapped around some wood filler.

I’ve drilled mild steel and aluminum before with no issue but this stainless steel worktop is frustrating me. I even got some cobalt bits and none of them seem to want to bite.

Using 20v cordless drill with moderate speed and moderate pressure applied.

Thanks in advance.

 

[SCWOOD]

try smaller bit first something like 1/8".

 

[eacmen]

try smaller bit first something like 1/8".

Thanks, started with the 3/32 bit and it didn’t budge. Just makes a nice polished concave divot.

 

[nadogail]

What kind of cutting oil are you using? I like TapMatic.

 

[eacmen]

What kind of cutting oil are you using? I like TapMatic.

I usually just use wd-40 or engine oil. Figured any lubricant should do the job. Am I way off base?

 

[Machinitect]

If you have been trying a while with the drill bit heating up, the stainless may have hardened. Try center punching it and use some cutting oil. If you can, shift your hole location over a bit to start fresh. You can’t let the drill bit spin and spin while heating up on stainless. Apply a lot of pressure and keep going once you start drilling. Use a fresh drill bit. Let us know how it goes.

 

[rkevins]

use lots of pressure and slow speed, that's how we did in the HVAC plant I worked in

 

[gizardlizard]

Second the cutting oil. Lots of down pressure too. Stainless can be a ***** to drill. I drill it on a mill whenever possible. Can be a challenge when hand drilling.

 

[eacmen]

Thanks everyone. I don’t think I let the bit get that hot to work harden the surface (i learned that the hard way a long time ago).

I’ll try to get some real cutting fluid and try again.

 

[isb cornbinder]

I use https://www.bing.com/images/search?...g+paste&form=IGRE&first=1&tsc=ImageBasicHover when drilling stainless steel. It is important to start with a sharp drillbit. Do not let up or stop drilling until the bit has gone through the work. Do not let a little smoke trick you into stopping, if you started right.
Stainless immediately gets as hard as glass when it cools.
I have never seen a cobalt drillbit. I am under the impression the cobalt is only a coating.
I have a set of carbide drills in the popular sizes just for my stainless drillings.

 

[theoldwizard1]

Start with a good punch, so the drill won't walk. Move up to a center drill. Now you have something a regular drill bit can bite into !

Start with a small bit and work up. This is where cobalt drill bits are worth the extra $$ !

 

[mcbane]

Who makes the cobalt bit that failed? If it is a HF “cobalt” like bit I can understand the frustration. But I have never seen a quality cobalt bit with lube and at proper RPMs struggle in stainless. And I regularly use cobalt step drills to put up to 1/2” holes in stainless sheet metal.

 

[DGersic]

Low speed, high pressure, lots of cutting oil. Carbide is especially helpful here. Heat is your enemy when drilling stainless.


Sent from my iPad using The Garage Journal mobile app

 

[timgunn1962]

Drilling Stainless is all about technique.

It work-hardens VERY easily.

"Moderate pressure" is almost certainly the problem.

Each pass of the cutting edge leaves a work-hardened layer beneath it. This is very thin and, when things are working well, the next pass of the cutting edge is through the unhardened layer just beneath.

When things go wrong, the drill doesn't move forward and the next pass of the drill doesn't cut, but slides over the work-hardened surface, work-hardening it more.

The drill will (often) become blunt and the problem will just get worse and worse until the operator gives up.

The only realistic way out of this that I know is to stop immediately the drill stops cutting, change for a new/sharp drill bit and start again, with enough feed pressure to cut through the work-hardened layer on the first pass.

Cobalt drills do seem to give a little more time between the first non-cutting pass and the drill becoming too blunt to get through the work-hardened layer on a restart, but it's not a big difference IME.

Cobalt is not a magic bullet. I suspect that a lot of the guys who know enough to use HSSCo drills are also the guys who know how to drill stainless (and stuff generally) properly.

I would not recommend using HSSCo to the OP. I think the fundamental problem is technique. HSSCo tends to be harder than HSS, but also more brittle. Adding (expensive) broken drills into the mix seems unlikely to help much.

I would recommend using new short (stub-length) drills, which are stiffer and easier to keep intact in small sizes, centre-punch the hole as emphatically as possible (to disrupt the work-hardened layer) and to drill in steps, starting with a 3/32" or 1/8" drill, low-to moderate speed and firm feed.

 

[matt_i]

Your whole body weight on the drill isn't out of the question, I'd try that around 3/16" dia.

Thrust on handheld vs. a drill press is considerably lower.

The DP also applies the axial force concentrically so you don't wobble and break the bit by bending it. But alas, drill presses don't work that well on large workpieces....

If the material is hardened and the hole location(s) are set, then you'll have to wear out the material, Dremel or Foredom tool are excellent for using carbide, porous stones and or low speed diamond tools to carefully wear the material away. Never do I recommend using a solid carbide drill bit in a handheld tool unless lighting a $20 bill on fire is of no object to you.

 

[eacmen]

Wow lots of useful information fellas. Much associate it. I struggled with many of these issues when first trying to drill metal, and I thought I had become pretty good at it until this project.

Ordered some actual cutting fluid and a real center punch (been using some chinese ****).

The one thing I’ve never skimped on are drill bits though. The cobalt bits I got were from Dewalt. Also have titanium stepped bits from Dewalt as well. Both high quality.

Might need to just get some scrap stainless to practice on, Started two attempts so far on the workpiece and want to avoid marring it any further.

Again thanks for all the info gentlemen.

 

[techieman33]

I have never seen a cobalt drillbit. I am under the impression the cobalt is only a coating.
I have a set of carbide drills in the popular sizes just for my stainless drillings.

Cobalt bits are quite common. And at least in real cobalt bits it's actually part of the alloy used to make the bits. Maybe your thinking of the "titanium nitride" or "black oxide" bits that are common in store and those are just a coating on the bits.

 

[WarDamnEagle]

Perhaps a stupid question, but what kind of bits are you trying? Assume normal pointed bits for metal, wood, etc? Just wanted to make sure you aren't trying brad points for example. I'm sure you aren't but thought I would ask.

I have had a large set of Saber cabinets for years. I really like them but I have cabinets on both ends of the worktop as well as cabinets under and over so never had a reason to drill the top for a vise (or anything else for that matter). I think you'll find MDF under the stainless.

 

[SamuraiJack]

Like the other have said a good smack with a center punch (like really hard) and step up with a cobalt bits should do the trick. Maybe the bits need some sharpening? You will have to use an unreasonably large amount of force. Stainless looks nice but is the worst to work with.

 

[Renegade1LI]

Use rapid tap & good USA cobalt bit

 

[Milton Shaw]

A set of Bad Dog drill bits have drilled through anything I have tried. I wanted a hanging hole in a 16" stainless pizza cutter. Other bits in a drill press would not bite into the metal and just kept sliding around. A Bad Dog bit cut it like was wood. They are fantastic for problem materials. Look on line for them. They also have a lifetime warranty and so they are a lifetime investment.

 

[Spencer Was Here]

I didn't read all or even most of the replies, so I apologize if this has already been covered.

Use 135-degree split-point bits. Get the shortest bits you can and chuck them up in your drill as far as you can.

The smaller diameter 1/8th inch bits I recommend you start with will bend slightly under the type of pressure you should be applying if they were to be sticking out of the drill chuck too far.

With that said, that is the amount of pressure you should be applying. Enough to slightly bend or even break a longer 1/8th inch bit.

Go slow and use a lot of force. Don't use a punch to start your hole. Even a punch can start the work-hardening process.

 

[MJD1]

Anchor lube and slow speed with as much pressure as you can get on the drill.

 

[tinmanwpk]

I work with SS for a living. Like many have said, drill slowly. Slooooooow. Use anything for cutting oil, even used car engine oil. Use plenty of pressure. And Spencer Was Here mentioned 135 degree split point bits. That is right on the mark!

 

[eacmen]

Finally wrapped it up. Way more of a struggle than I anticipated.

Definitely learned alot from everyone here.

Lessons learned:
1. Pressure is everything, basically ended up putting most of my upper body weight into the drill.
2. A good Starret center punch is worth the cost.
3. The Dewalt cobalt drill bits with the “pilot point” work really well. But not all bits in the set have the pilot point. I had no luck with the 1/8 bit, stepped it up to a bigger bit but with the pilot point and it bit right away.