Drilling hardened 12C27

[e_utopia]

I need to put some holes in hardened (56-58 Rc) 12C27 stainless. Okay, I don't actually need to, but you get the idea

The holes will be 0.100" (and maybe some smaller ones; I heven't decided), and I'll also want to bevel the edges of the holes slightly, so I'll need appropriate countersinks/de-burring tools (my brain is on the fritz; I can't remember which one I want, or if there's even a difference). Any recommendations as to what bits I need, and where I can get the bits I need, without buying a whole set?

--thanks,
JB

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e_utopia@hotmail.com

 

[C L Wilkins]

Carbide bits. You can get them at any of the industrial supply houses such as J&L, MSC or Wholesale Tool.

As far as sets (drill index), they are useless. Only get the bits you need. I don't believe anyone offers a drill index for carbide anyway.

 

[Jerry Hossom]

How thick is the steel? Carbide will cut it, but you need to be careful and use plenty of cutting fluid. You might find the bevelling easiest with an abrasive wheel (cone shaped).

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Jerry Hossom
www.hossom.com
The Tom & Jerry Show

 

[Ron Peek]

The other thing to remember when drilling with those carbide bits is to back up the piece you're drilling with a piece of scrap steel so the bit doesn't suddenly break through and turn into 4 or 5 bits, each more or less useless.
Ron

 

[e_utopia]

Thanks for all the info. The steel is 1/8" thick (give or take a little; my verniers are getting worn a bit). I guess I'll be giving MSC a call.

--JB

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e_utopia@hotmail.com