Tips For Drilling Stainless Steel

[MEXICOWANDERER]

"Tips" does not denote authoritative last-word instructions, rather ideas that help folks who are first timers or frustrated second timers.

Very expensive made-in-USA (Germany / Sweden) drills are worlds apart in effectiveness and durability than Oriental drills. In fact I have had better luck with uncoated M2 drills than with so-called titanium plated Oriental drills.

Made in USA, titanium plated drills are excellent but they are prone to damage if spun at too high a speed even for a few seconds. When the titanium disappears from the point the drill is simply plain M2 steel.

Carbide drills are fragile. They are harder than any other drill but one malforned curl in the hole can chip the tip. I have no idea how to sharpen a chipped carbide drill.

Cobalt drills are solid specialty steel. Good quality cobalt drills can be a lifetime investment if they are resharpened correctly (another thread).

I do not know of a way that stainless steel can be drilled rapidly. In fact speed seems to be the big-enemy of anything used to try and drill A4, 18-8 or 316 stainless steel.

But I stumbled across a tip that really surprised me...

WD-40, cutting oil, tapping oil or whatever is not the best stuff to use when drilling stainless steel. Not by a long shot.

Make up a sprayer pump bottle, maybe a pint. Put one tablespoon of liquid dishwashing soap and slightly less than a half teaspoon if liquid clothes washing bleach in with the water and fill the bottle.

A gunsmith machinist patiently explained that "Lubrication is definitely not what the drilling process needs. It's cooling of the work area and tool. Soap makes the water "wetter" and water is far superior to oil in carrying away heat. The bleach makes the cutting action more aggressive".

I would believe there is a limit as to the capacity of the mix to cool the bitter edge of a cutting tool so lower speed is still essential to not destroying the cutting tool.

I've been using this trick for years and now I used it when drilling regular steel. It really works and in the end the far easier and more complete cleanup of water versus oil makes it a winner in my mind.

Sometimes in stainless steel I drill at 60 RPM so slow is mandatory.

You bet! Comments are welcome!

[Tom_Barb]

Use a very sharp split point drill and run it really slow, any heat dissipating liquid works as a coolant.

[theoldwizard1]

First rule is use a center punch and make sure to ACTUALLY punch it in the center of where your want the hole.

Second rule is to use a center drill to make a pilot hole.

Time has proven, COO (country of origin) DOES matter. US/Germany/Sweden will typically beat anything out the far East.

One "new" US brand in Drill Hog. Sold exclusively on eBay and Amazon. Their least expensive drills are made from M7 High Speed Steel. Plus they have a LIFETIME warranty !

The unproven "Internet rumor" is that Drill hog is buying large quantities of individually sized bits from well known US manufacturers and then repacking them and selling them as sets. They are not as cheap as the bits from the far East, but they are much cheaper than the traditional bits sold in tool stores !

[path1]

Thanks... any tips on thin stainless not turning blue? Is blue from heat? If so maybe go slower?
Thanks

[SAR_Tracker]

Use a center punch too!