1 Nov
2007
1 Nov
'07
6:13 p.m.
On 1 Nov 2007 at 22:36, Tony Duell wrote:
The wookshp manual [1] I have alongside me gives the
removal method as
drilling a hole down the middle and then using an easy-out. Does that
term exist across the Pond? It's a tapered tool with a left-hand thread
on the otuside. Put it down the hole, turn it anticlockwise with a tap
wrench [2] and it bites into the sides of the hole and turns the
shear-head olt anticlockwise too.
Easy-outs, like tap extractors are perfect examples of oxymorons.
I've never found an Easy-out that will remove a really stuck sheared-
off bolt, nor have I found a tap extractor that will remove a broken
tap.
I've come to the conclusion that most people who have success with
tap extractors buy really cheap taps that break if you look at them
crosseyed. A good tap, when it breaks is impossible to remove with a
tap extractor.
A very slick way to remove a steel bolt or tap that's sheared off in
an aluminum casting (e.g. a hard disk body) is to use nitric acid
and a little heat--the acid doesn't bother the aluminum but eats
enough of the steel to loosen it for removal. I've heard that alum
(I don't know what sort, probably amonium) also works.
Cheers,
Chuck