[AT] Northern Tool Sale - Left Hand drills

CEE VILL cvee60 at hotmail.com
Tue Dec 27 16:59:31 PST 2005


Reading thru the comments of this thread, I can confirm a couple of them.  I 
have had 45 years of time in a precision Swiss screw machine facility, so 
have been there and done that to some degree.
All to often, a screw machine operator or set up guy would use too much 
muscle on small size bolts used on the machines, usually 4.0 mm to 8.0 mm 
range.  Gary's statement here that LH drills will only remove a broken bolt 
that is "free" is very true.  Often our bolts would be broken flush with the 
mating surface and have a rough edge or spur into the cast metal.  Commonly 
I ground the surface clean to remove this and give a flat ent to center 
punch, then in with a LH drill.  Walla, out comes the bolt stub.  No rust in 
that environment.
Pretty ineffective with a bound or rusted bolt.

On a side note to Ted:

Inconveniently, our Swiss machines all had LH main spindles,  Therefore, LH 
front end working drills had to be used unless overlapping speed was used.  
I purchased many of them over the years, and agree that drills from 
Cleveland Twist Drill and Greenfield Tap & Die are top shelf.

Charlie V.  in damp WNY


>From: K7jdj at aol.com
>Reply-To: Antique tractor email discussion group 
><at at lists.antique-tractor.com>
>To: at at lists.antique-tractor.com
>Subject: Re: [AT] Northern Tool Sale - Left Hand drills
>Date: Tue, 27 Dec 2005 00:53:25 EST
>
>In a message dated 12/26/2005 9:08:26 PM Pacific Standard Time,
>deanvp at att.net writes:
>
>"I have heard two many stories about stuck broken off bolts
>and studs  coming out by themselves when using a left hand drill. "
>
>The Northern Tool set is on backorder now, but I went ahead and ordered a
>set.
>
>I've had the experience!  On my JD350 rear crossbar attachment  bolts.  I
>must say these bolts have broken several times and I early on  started 
>using
>"never seize" on them. I doubt that their is much benefit if the  reason 
>the bolt
>or stud broke is due to it being rusted, bottomed out, or any  other such
>reason. I've also been lucky and had the bolt come out when I "stuck"  the 
>drill
>bit and then reversed the drill motor to "unstick" it.  I too  have done it
>all, broken easy outs, made a mess with a torch that required  rethreading,
>welded a nut to what's left, and just about every other method  including 
>bad
>language with varying results. I have especially poor luck with  fine 
>threads.
>Seems like they, more times than not, "gall."  Even the  larger sizes give 
>me
>trouble with galling.  I suspect some of my failures  might have been 
>avoided
>with a little more patience.
>
>Gary
>Renton, WA
>
>_______________________________________________
>AT mailing list
>Remembering Our Friend Cecil Monson 11-4-2005
>http://www.antique-tractor.com/mailman/listinfo/at





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