Self tapping or self drilling? I presume you need the self drilling
ones. McMaster has them in dozens of sizes for not so great prices. I've
been paying about $6/100 for the smaller 1/4" drive in #8 screw at my
local home store. We also get the pole barn ones with the rubber washer
under the head. Haven't used them lately, no idea on a good price. Looks
like stitcher screws are short versions of the pole barn screws.
These have the 5/16" heads, and the rubber washers. I'm finding them in the
twelve to twenty cent range. I need a lot of them, hence, trying to get a
deal. Will go by the old fastener store in Vegas when I'm there next. I
got enough, and can buy some at the Borg for the drilling into purlins, etc.
Would like to have the exact model I want, though. Doing it right the first
time is the only way to go.
The "stitchers" have a shoulder, and once the drill has done its work, if it
goes into anything thick, it will shear off at the beginning of the threads.
They are meant for stitching two sheets together along the seam where the
first ridge overlaps the next sheet. Once it's in, it will turn another
quarter to half turn, pulling the two sheets together and closing the space.
Not actually sure of the right term yet.
At seventeen cents apiece, we're talking over $250 just for screws.
It's always something.
I did find these guys, no prices listed. Probably worth a call for your
or these guys at $.06 each in larger quantities
The straight shoulder, I'll call them, the ones that have the same thread
size as self tapping drill are no problem, although this is a very good
price, even though you need to buy 2,000 of them. But, as a lot of
fasteners, if you can use them over a couple of years, it's a very good deal
to buy quantities, as small packs are horribly expensive per unit price.
Where I am having the problem, is with what I call stitchers. It is not
like a lettered drill size, and a corresponding tap. With a stitcher, if
you use the drill tip size for a pilot hole, when the threads hit the
drilled hole, it snaps off because the threads bell out. This is by design.
These are only meant to stitch two sheets together along a ridge, or edge,
or to attach the edge trims to corrugated roofing and carports. You cannot
use them to attach a sheet to a purlin.
These are very common in the industry, but I haven't gone to Vegas in a few
weeks. I will be in Cedar City, where there is a Fastenal, off and on for
the next two weeks, and have talked to them. I can bring the screws in, and
they can match.
Then there's the washers. I would really prefer the cup/head washer where
the 5/16" drive head and cup washer are one piece with a full 1/8" thick
washer in that. On most neoprene sealers, you can twist the washer off.
It's bonded to a metal washer, but you can spin it off. With the "really"
good ones ($$$), there is a better ultimate seal, as there is no space
between the washer cup and head.
I was out on the project at 0530, had to turn on the lights for the first 45
minutes or so. Finished some little things, removed the temporary lights,
and am ready to paint frame. Just want the right screws when I'm ready to
slam on the sheets. Am working either 0530-1100, or 2000-0000 to escape the
It sure is nice that time of day around here.
Coyotes have been singing at dawn and dusk lately. HUGE crop of rabbits
this year, so should be lots of coyotes.
Speaking from ignorance, I did not realize how littlle I knew when I
hung verticle corregated panels as walls to a shed. I used TEK screws
with washer heads to attach the panells to the metal frame and pop
rivets on the verticle seams. I fell in "Love" with the pnneumatic
No jackrabbits or coyotes either.
Pop rivets along the seams would be an alternative. AND, I have always
wanted an air pop rivet gun ..........The purpose of joining seams is to
reduce harmonic resonance, and subsequent hole elongation leading to
failure. The stitchers are just so much easier to use.
Pop rivets - I have a few. But the real stuff - Mil spec Al rivets -
I have a bunch of. They were left overs from work on an B-52 air wing.
Left overs are trash unless taken care of and kept to spec. These were
mixed. Oh rats.
On 8/24/2011 10:27 AM, Steve B wrote:
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