[modeleng] Re: How do they make that? Twist drills w/holes

Alan,

When I attended the Chicago Museum of Science and Industry in 1949, they had 
examples of the way twist drills were made.  They started out as straight 
rods with flutes  which were then twisted so you see, you are correct in 
them drilling straight holes and then twisting the material .  What is 
amazing to me is that they were able to get such tiny holes through there 
straight enough to not break out through the sides.  I suppose they did it 
as the old time gunmakers did, i.e.: Rotate the work instead of the drill. 
If a drill is properly sharpened and the work is rotated, the drill will 
make a straight hole and this is especially true of "gun drills" which have 
only a single flute.  They not only drill the hole straight, but practically 
ream the bore at the same time.  I drilled the long 5/16" holes in the 
trunnion of my Filer and Stowell with "long boy drills'. and all 6 holes 
went perfectly true, but I know of at least one example wherein the drill 
was rotated in a milling machine and the hole wandered off track despite the 
work being set up perfectly plumb.

Oh, forget the Chicago Museum.  I was back there about 20 years ago and the 
place has been mostly stripped of all the interesting stuff in favour of 
hip-hop graphics and ethnic crap.

Maybe the box joint pliers John talks about were made like the wooden pliers 
I carved many years ago, with a thin knife blade???  I doubt that though, 
and am as curious as he is as to how they make the joints in steel.  Those 
Pakistanis are pretty slick with their box joint surgical tools.  Any 
Pakistanis on this list??  How 'bout it mates?  How is it done, especially 
in stainless steel???

Jesse the dried out machinist in Troy, Tennessee.  Maybe it will rain some 
day??? 

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