drilling stainless steel

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its_virgil

its_virgil

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Wichita Falls, TX, USA.
I need to drill 200 holes in pieces of 1/8 inch thick stainless steel. So far no luck. I've used a punch to mark the holes. Changed the speed of my drill press from slowest to fastest and all I have so far is 3 holes and 5 smoked bits. Any help appreciated. I think a lubricant may help. Any other advice?
Do a good turn daily!
Don
 
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what size holes? What type of stainless, 300 series or 400 series? Is it magnetic.
your drill press, if a standard home type, may not run slow enough to drill stainless. Stainless, especially 300 series, (non magnetic) must be drilled slowly and with a steady feed. hand feeding may not work, you need power, steady feed.
and yes, coolant or lubricant is almost required or you will have to slow down even further.
 
Don:
The VERY FEW times that I've drilled 1/8 inch stainless steel plate (440 stainless), it required a special diamond tipped bit (very expensive), a drill press that would slow down to <300 RPMs, and a "cutting oil".

Needless to say, this was a cumbersome process. We ended up having a welding shop make a "template" and cut the holes with some type of plasma cutter.

I wish I could help, but I've had very little success drilling plate stainless.
 
Try slower rpms, steady heavy feed, and cutting oil.
Stainless is the type of material that is tough and does
not want to "let go" of chips, and will work harden under the tool
if rpms are too high, and feed not engaged pretty firmly.
A home brew cutting oil can be had from kerosene and lard, with maybe some beeswax mixed in. I know, try finding lard today...:biggrin:
Best of luck, Don!
 
Thanks for the help and comments. My drill press will go down to 220 rpms so I think I have that covered. I will find the drill bits suggested, get some cutting oil and try again....after I get back from New York City to see my new and first and only grandchild.:biggrin::biggrin: Mother and father are completing their residencies (medical doctors) at the end of June and will be moving to Pittsburgh...a little closer, but not much:frown: for more training..fellowships I think they are called.

Thanks again for the help.
Do a good turn daily!
Don
 
Don:

Try getting a couple cobalt bits, slow speed down so the material doesn't work harden, consistant feed rate, and if you can flood coolant, if not try some sulfer oil, or you could take it to a sheet metal shop and just have them punch the holes.

Also increase the the cutting angle on the drill bit, use something like a 135 degree point (in other words a flater point), less surface area to cut.

Good luck.
 
The trick is to not overheat the metal. Once it does, the tool will die immediately. Following a hardened half drilled hole with a fresh drill will only kill that one too. Use the slowest RPMs you can get and flood that sucker. There are synthetic coolants that you add water to, and those come from industrial supplies, like MSC and others. It has to be cool. Cobalt drills are an improvement over HSS, and carbide will handle higher heat at the expense of being more fragile. You can use a stub length drill to make it less likely to snap. I actually use a straight flute solid carbide drill on my titanium. The straight flute makes it a lot stronger, so breakage doesn't happen as much. Machine and part stiffness will play a part also. If the sheet can move around, that slight deflection might be enough to fracture the fine cutting edge or snap the drill entirely. Less movement of the sheet is better.

If that doesn't work, go with the laser. :wink:
 
The 50 pack for 10 bucks at harbor freight is not the way to go with SS. LOL. When I had stainless to drill at work I would wait till the boss was not looking and order Cobalt bits. He complained because of the cost, but 1 would drill a LOT more than the bits he was getting from the store room. (Wait until you have to drill a hole in a piece of stainless with a hole saw, without a mag based drill.
 
This is what the guys in our machine shop use when they were machining some SS for me: HONEY

They swear that its better then cutting oil for SS

And yes, they used the containers that were shaped like a bear

And no, this is NOT a joke
 
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