Left hand drill bit

wmg73141

Well Known and Active Forum User
Non-VOC Member
From experience I can confirm that left handed drills can and do often work as shown.

The down-side is that it is not often that threads break that deep in a hole, more often the blighters break at or near the top! If that is the case those sprung drill guides and drilled bolts will not work.

The fact remains however that the most important thing is getting the drill dead centre and axial with the offending thread. Where there are other threaded holes on the same face it is worthwhile making a drill jig bolted on using those holes. Old toolmaker's saying:- "The time spent making a jig is never wasted."

If all else fails then careful enlarging of the hole to the core diameter of the thread will usually make it possible to 'unwind' the remains of the thread. Another good reason or careful centring! Most holes for threads are sized to produced 70% of the nominal thread depth so there is a small margin for error but not much before you hit the thread you are trying to save.

Think thrice, measure twice, cut once . . .
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Never seen a drill like that for sale, Thought it was a Joke at first !. Good idea about making a jig from other holes.
I have done it the hard way in the past, Pot Luck !, But been lucky, Not good for my stress.
I was a self employed Car Mechanic for many years, So it was all down to me.
Cheers Bill.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Thanks Bruce, I will pop down there.
The Wife bought me some Rubber ones last year, At a Boot Fair, Never had a drill bit Bend on me before,
Most strange. Cheers Bill.
 

erik

Well Known and Active Forum User
VOC Member
if the left Hand threaded tool breaks ,than you have an other Problem because it is hard.if a 10 or 12 mm bolt shears then the rest is nearly bomb proof fixed in the hole and the Extractor with ist small Diameter works only good in theory.i would use additional heat to do the Job.
 

davidd

Well Known and Active Forum User
VOC Member
Tig it.

This one was standing proud of the case, but I have done broken studs in Vincent cases that were broken about 1/4" down.

Broken Stud 2.jpg


Broken Stud 3.jpg

The heat of the torch does a good job. This one, I had to heat with a separate torch and weld the rod back on about 5 times before it let go. Normally once is enough. This had salt water to deal with.

David
 
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