[modeleng] Re: 'oles

  • From: Doug Edwards <stueart@xxxxxxxxx>
  • To: modeleng@xxxxxxxxxxxxx
  • Date: Mon, 07 Mar 2005 07:37:18 -0800

I agree with what Jesse has said, and will add a couple more comments. 
 I thin the web of the
drill when drilling hard stuff.  On the standard sharpening of a drill, 
the center part of the drill just
rubs against the material, which promotes work hardening if care is not 
taken.  I also find a
heavy center punch on location tends to help.  A sharp drill makes the 
job go a whole
lot easier.  

I no longer buy HSS endmills under 1/4".  Over all in the smaller sizes, 
carbide is a whole
lot cheaper for what I do, and carbide will go through the spring steel 
very easily.  

My personal first choice would be to punch the hole.  I remember plans 
for a small
hole punch in ME in the mid to late 50's.  It has been on my to do list 
for a number of




>Spring steel can usually (noticed I said USUALLY) be drilled by running the
>drill very slowly, using plenty of thread cutting oil and keeping a steady
>and relentless pressure against the drill bit.  If the drill ever makes a
>turn without removing metal the steel will instantly case/work harden and
>all forward progress will cease.  This same system works on stainless steels
>that work harden when drilling.
>Unka Jesse
Doug Edwards
Building a 70 ton Willamette in 1.6"
Building a 80 ton Climax in 1.6"


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