[AT] Bending a hook on a spring

[Steve W.]

George Willer wrote:
> Len,
> 
> The original spring was most likely made without any heat at all, after the
> heat treating was done while it was still straight wire.  Rusty and pitted
> is bad news because the pits are stress raisers where cracks can begin.
> 
> If you do try to use heat to form the loop, it's rapid cooling that will
> cause brittleness.  Slow cooling will cause the heated area to remain
> softer.  It's worth a shot if the normal use doesn't tend to make the
> softened loop fail.  The black smith way to cool slowly... drop the hot
> spring in a bucket of wood ashes or lime.
> 
> I have to make a lot of pedal return springs for my (16) Cubs.  I do it
> cold.
> 
> George Willer
> 

Very few springs are made hot. It's hard to control the end result with 
hot material. Coil springs are formed with a rolling former. The ends 
are formed as an integral part of the forming process. As the size of 
the wire goes up they just increase the size of the machinery. Watching 
automotive coil springs being formed is a strange thing. They start with 
the straight wire, feed it into the machine at the same angle the coils 
are set at. Takes about 30 seconds for the entire process!

-- 
Steve W.
Near Cooperstown, New York