Jay Honeck wrote:
Okay, that said, why is it that everyone (that I've seen, anyway)
continues to use the (too easily strippable) Phillips screws?

The one problem I've run into with internal Torx screws (on cars) is
that if there is even a little bit of crud in the recess in the screw
head, the correct-size bit doesn't want to fit and the next size smaller
bit will feel like it fits just fine. If the screw is holding down a
piece of trim you can get away with it. If there's a lot of torque on
it, the too-small bit will strip out and maybe damage some of the lobes
on the screw head. The two ways around this are 1) make sure the screw
head is clean and 2) if you're not sure what bit a Torx screw takes,
once you've found one that seems to fit, get the next bigger one and
make a good effort to fit it in the screw head - don't use a hammer,
but do more than just hold it near the screw head and look at it.

Inertia?

Yep.

Cost?

Yep. I think any patents on Phillips had run out long before any
patents on Torx. On the other hand, you'd think if anybody would use
Torx, Cessna would, because at one point or another they are/were both
part of the same conglomerate, Textron.

No one has thought of it?

Nope. There is nothing new under the sun.

No one else cares, cuz their A&Ps do all the work?

Maybe some of that. I think your "average" GA pilot probably _knows_
more about turning wrenches than your "average" car driver, but that
doesn't mean they actually turn the wrenches themselves.

You might care more than the "average" because you're probably used to
doing maintenance things around the hotel, where you have a lot of
discretion on changing the design. If the nail keeps pulling out, use
a wood screw. If the wood screw keeps stripping out, use a bolt and a
nut. No paperwork, just your own judgement and "try it and see".

One factor may be support. Every A&P is guaranteed to have regular
and Phillips screwdrivers and bits. Torx may be common enough now
that the bits are in all the tool chests as well, but maybe not. If
you put a lot of Torx screws on your plane, it might be cheap and
light insurance to carry a set of Torx bits.

Personally, I think good-quality Allen (internal hex) screws are the
One True Screw[tm]. The drive tool doesn't slip out. They are older,
so the bits/drivers for them are more common. They are second only to
slotted screws in their ability to accept improvised drive tools - this
is a feature if you're trying to fix something while stranded at East
Armadillo Toe International Airport and a bug if you're the _next_ guy
to have to touch that fastener.

Matt Roberds