Drilling through stainless steel

[Symphony]

Last June I splurged on a small bottle of cutting oil - what a difference in clean up, worry about dripping, etc. an excellent purchase.
A small bottle will last long time and doesn't cost much - highly recommend for drilling SS

[Cadence]

Originally Posted by HopCar

How about avoid drilling holes and use clamps like this?

A damn good idea.

[bcboomer]

Just want to add that not all "Professional Marine Technicians" know how to drill stainless steel.
That was a very expensive lesson.

[lewisa]

I strongly second the recommendation to use a carbide drill. They make the job easier, faster and safer. And while they are more expensive, you probably need to buy only one of the correct size. Because boats tend to have lots of stainless steel, it might be well to invest in a set of fractional or metric carbide drills. You'll be glad you did.

[Pete7]

Originally Posted by Wotname

If your scarf is coming off in two nice spirals, you have the right combination of speed and pressure.

Yep, normally say something similar to my ski students before setting them off from the top of the mountain. :-)

Pete

[skenn_ie]

Cross-tip or Cobalt drill, and cutting compound/fluid. Rocol is good, but I am allergic to it !. I don't even need to get it on my skin. Oil/WD40 makes very little difference. Slow, and considerable pressure. Stainless work hardens in an instant, so any slipping of the drill will make it even more difficult. You can drill with HSS, but it needs to be very sharp. Cobalt is very brittle, so ANY bending of the bit will break it.

[Scott Berg]

lots of good advice (slow (very!), hard, sharp, bits... but the key is having a good jig. you can buy one or make one using piece of wood, just cut a hole (using a hole saw) the size of the tube, then cut it in half and bolt it back over the tube; they you drill through the wood into (and through) the tubing. Keeps the bit straight so you can focus on pressure (lots) and speed (none)

[Carlisle Spirit]

Unbolt and get a stainless fabricator to drill your holes

It’s a seriously inexpensive option compared to the cost of equipment and time needed to do it properly

[RedFeather]

I have the same problem with our swim ladder. Was thinking I’d just cover the steps with cheap pool noodles, cut to the width of the steps and spliced lengthwise to stretch them around the steps.

[rbrake]

All the basics have been covered. Lubrication, speed and pressure. A drill jig will aide 100%. I keep a 1" piece of delrin scrap around to make an impromptu jig. It just gets full of different sized holes. You find you really don't need that many. Concerning bit material, plain old high speed steel, HSS, is all you need. All the titanium, platinum, gold and whatever are just fractional mil coatings for marketing. When it comes to drilling through metals the first couple rotations will eat off all the coatings. Carbide bits stay sharp but are extremely brittle and expensive, more in line with an auto feed drill press and a production line than for hand drilling.

[Cadence]

Keep in mind cutting oil is more for dissipating heat than a lubricant. Keep it flushing the work surface.

[tstano]

Why not just make the treads wide enough to clamp around the stainless. Now you won't have salt water seeping into the rungs and rusting from the inside out. Can't understand why anyone would buy a boat and then start drilling it full of holes.

[DEC2017]

If it’s 300 series stainless it work hardens very easily. You must keep the pressure constant on the drill to keep it cutting continuously.

[jag39]

All it takes is a Cobalt bit. You can get them at Lowe's or Home Depot. Piece of cake. Not the brand name Kobalt, which is something HD sells, but an actual Cobalt bit. Just read the label.

[Robert Jansen]

First, locate an industrial hardware store. Don't even bother to try to find what you need at a lesser institution. Purchase carbide bits and request advice on which cutting fluid to use (you'd be surprised how many there are from which to choose). Remember that carbide is sharp, but it is brittle, so consider buying spare bits, as it is easy to break them, especially when drilling small holes. A drill press is better than a hand drill, so in the long run, the task will be made easier by removing the ladder and working at the drill press. Don't forget the advantage of using a nail set to indent the stainless steel, so the drill won't try to walk on you.