On Thu, 08 Apr 2021 21:32:46 -0400, micky
wrote:

In alt.home.repair, on Tue, 06 Apr 2021 00:41:11 -0400, micky
wrote:

In alt.home.repair, on Mon, 5 Apr 2021 10:16:18 -0700 (PDT), Dean
Hoffman wrote:

On Monday, April 5, 2021 at 12:06:35 PM UTC-5, micky wrote:
I bought a USB charging jack designed for a car's dashboard, and
designed to fit in the same size hole as a cigarette lighter.

Many versions for sale. This one, no more expensive than the others,
came with a hole saw for 1 1/16", a size I don't have**. The hole saw
has the shank, the center drill bit, an allen wrench, the hole saw
itself, and a spring!!!

A tapered coil spring whose small diameter just fits the bit. Is that a
coincidence? What is the point of the spring? I've used a hole saw
before and didnt' feel a need for a spring. Is it to force out the hole
after it's been cut? Have you seen this before?


https://www.wonkeedonkeetools.co.uk/holesaws/what-are-the-parts-of-a-hole-saw


This one doesn't have slots. I'll see if the spring is too strong or
not in a day or two, when I drill the hole.

Thanks all.

Well, I was a little taken aback by the spring. I knew it was there but
I still didn't understand at first what was pushing back. i thought it
was the rubber mat glued to the other side of the plastic.

But when I was done, the spring did not force the cut-circle out of the
saw. Becaue the spring itself cut a hole in the plastic. Twice the
size of the bit in the middle, but smaller than the 1.1" hole saw. So
the spring poked through the hole it made and the "plug" stayed in hole
saw. It might work better with something other than 1/8" plastic.


Cutting plastic use a "fender washer" just smaller than the hole with
a center hole big enough for the pilot drill