Drilling Stainless Steel

Jeff M.

Jeff M.

Joined
Jan 5, 2005
Messages
213
I have a folding blade that I want to put a larger pivot pin in, 7/16". I picked up a drill bit that was for SS, but it still wont work! Anything else I can do?
Thanks...
 
If it is already hardened then you will need to buy a carbide drill bit.
 
You'll also want to drill under size and use a carbide reamer if you want a good fit for the pivot.
 
Have any of you done this? If I use a carbide end mill right at 7/16", it should be perfect for the pivot bolt/pin. But will a carbide end mill cut the SS. Its ATS-34.
 
Hi Jeff - sorry, I didn't know for sure if this would work, so I didn't want to answer. I spoke with my mentor, Alan Folts and he confirmed what I suspected which is that you will have an impossible time trying to center on the existing hole. The mill will have to be large enough to make a new hole and possible change your pivot point. With a drill and reamer you will be able to center on the hole and keep things precise.
 
Jeff M. said:
Have any of you done this? If I use a carbide end mill right at 7/16", it should be perfect for the pivot bolt/pin. But will a carbide end mill cut the SS. Its ATS-34.
Click to expand...

Yes, but I would STRONGLY take the suggestion above of undercutting and reaming, with a reaming end mill. You may want some of the thicker cutting fluid as IMHO works better for stainless, and work slowly can methodically with low RPM. Vibration is not your friend. You may want to have something backing the blade to the vice like a block of aluminum to keep deflection down. I'm not a pro though, just an experienced ametuer. The pro's may have an even better way... I've heard some guys argue one slow straight shot through the steel, some others like the soft taps against the steel to take out little by little. Buy a small stainless plate of the same thickness from somewhere like McMaster and test it first before your blade. Can't set you back too much more than a few bucks, but ruining your blade will.

Also, for centering, you'd probably want a CNC to make that work well, but you could try and eyeball it. In the end, a local shop should be able to do all this for you for less than $50.
 
By no means impossible to center on the hole, that's what indicators are for.

That being said, I would want to ream it personally....

Carbide might or might not cut it well, depends on how hard it is.
 
Brian Fellhoelter Knives said:
By no means impossible to center on the hole, that's what indicators are for.
Click to expand...

Yeah, centering it isnt my issue. I have the means to do that. But there is a local tool manufacturer just down the road, so for the cost of the other end mills/reamers, that I will most likely never use again, I think I'll see what they will do.

Thanks a lot for the help guys.
 
Hey Brian, Checked out your web page. Thats absolutely great work you do! Love those frame locks:thumbup: Very nice f&f, very clean!

Thanks again for the help.
 
Well I went to the tool manufacturer down the road, and they hooked me up, for only $25! Im all set. Thanks one more time:thumbup:
 
For yall's information:

CNC doesn't help you center on a hole, (though it does simplify milling a hole in hard steel). I center with a coaxial indicator, but you can use wigglers and find the center of a hole to about a thou in a couple minutes.

A down and dirty way to do this job on a humble drill press would be to press a pin in your hole, stick that pin in the drill chuck, then clamp it all down to your table. Now everything is aligned, so just pull the pin, install your cutter in the spindle and go to work.
 
Nathan the Machinist said:
For yall's information:

CNC doesn't help you center on a hole, (though it does simplify milling a hole in hard steel). I center with a coaxial indicator, but you can use wigglers and find the center of a hole to about a thou in a couple minutes.

A down and dirty way to do this job on a humble drill press would be to press a pin in your hole, stick that pin in the drill chuck, then clamp it all down to your table. Now everything is aligned, so just pull the pin, install your cutter in the spindle and go to work.
Click to expand...

Not directly, but I swear I've seen people write software for use with a CNC using indicators where the computer "searches" for the edges of a known shape (i.e. circle) and determines the dead center point and moves to it.
 
You probably did.

However, "CNC" just means "computer numerically controlled" controlled "what" is the question. I've run a CNC tube bender. That may have been a CNC coordinate measuring machine?

Some folks use Renshaw probes in their mills for in process measurements and automatic offset tweaks which could be used to locate holes etc - but 99% of us center on holes on a CNC the same way we would on a manual.
 
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