Ed Huntress wrote:
"Existential Angst" wrote in message
...
Awl --

Purpose? Applications?

The minor diameter of the fine thread (under 2") appears to be about .115
(mebbe less, due to inadequate penetration of caliper edge), and .090 on
the coarse. Ergo, more "grab" with the coarse.

I'm guessing the following:

Coarse thread is for sheet rock on metal studs -- more grab on studs.
Altho framing screws, which afaik are only for metal stud to metal stud,
also come in coarse and fine thread, so this may muddy this particular
logic. Mebbe for different gauges of metal studs? I've seen some much
heavier than others.

Coarse thread for particle board et al.

Fine thread for hardwood.

Opinions?

The Gougeon Brothers of sailboat fame did tests of coarse- versus
fine-thread screws in wood back in the '60s. Coarse-thread won. Sheet metal
screws beat wood screws in wood every time. That was before sheet rock
screws.


www.mcFeelys.com

About any screw you might want, and square drive is the ONLY option as
far as I'm concerned!

Stuart