"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.

Heh, I'm surprised that some here have asserted that it is the fine thread
that's used on metal studs, coarse for wood.
Not disputing it, just surprised that this would be so, as it would seem
that the greater the ratio of major to minor diameter, the more grab
possible on thin sheet metal.

In fact, there's a company that exploits this with some fancy sheet metal
screws -- forgot their name, but I have a sample pack from them somewhere...

In re-thinking all this, pilot holes could be used to tailor any material to
a coarse thread. Except that, well, altho pilot holes are good, they are
also a pita.

I used to buy only fine thread, pretty much out of reflex, but now I find
myself much more leaning toward coarse thread, overall.
Plus, coarse threads are easier to tap, less chip binding it seems.

My understanding is that fine threads on big bolts is a torque/force
consideration, for getting mating stuff really tight.

But, other than that, I think fine threads may be pretty much superfluous
for general applications, unless, for example, metal studs really do call
for a fine thread screw.

Bottom line is, I think I've convinced myself to dispense with fine thread
anything, unless an application specifically benefits from a fine thread.
Sure will simplify the organization/storage aspect.
--
EA





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?

fyi, there exists a 3/4" and 1 1/8 SR xcrew, very hard to find.
The 3/4 is VERY handy, when screwing from the back side of a good face,
and the 1 1/8 occasionally comes in handy.
A good hardware store, proly one that sells SR screws by the pound, can
order a 25# box. If he hesitates, tell him that the 3/4" will FLY out of
the store when people grok their utility.
--
EA