[SEL] OT////// AM transmitter - now homebuilding

[Dave Merchant]

New deck screws are coming thru in the US with T25 Torx heads.
Gives a real positive drive, but don't know how they'd be to remove
after a few years exposure.

Previously in the US, deck screws used a "combo" head, square drive
superimposed on Phillips. Gave a lot of engagement for the matching
driver, really worked well, but the T25 seems slightly better.

Cement board screws here have square drive, and it's real easy to
strip the square out to round, especially with the super-hard old pine
studs + joists in our old house. Worst is square drive in some stainless
screws we tried to use. The stainless is too soft, stripped out many heads.

Deck screws, at least in the US, have a very special coating, since the
enviro-crazies got the normal green pressure treated timber banned.
The replacement is also green, but is about 4 times more corrosive
to fasteners than the old stuff. (Manufacturer's statement, not mine!)

We built a scaffold last year from pressure treated + 1/2" chromated bolts.
Had it up for 2 weeks before dismantling it, and the bolts look like 
battery terminals.

In areas subject to shear loads, I use a combination of nails + deck screws,
the screws prevent pull-out, and the nails handle the shear.

Dave Merchant


At 06:28 PM 12/19/2008, Alan wrote:
>Hey Arnie,
>I prefer the square drive decking screws for screwing down the blocks on 
>my trailer.
>  This really helps the engines stay where I want them to.
>The square drive doesn't strip out like the Phillips drive ones do.
>
>Alan in Michigan
>
>--- On Fri, 12/19/08, fero_ah at city-net.com <fero_ah at city-net.com> wrote:
>
>From: fero_ah at city-net.com <fero_ah at city-net.com>
>Subject: Re: [SEL] OT////// AM transmitter
>To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
>Date: Friday, December 19, 2008, 11:10 AM
>
>Hi Dave,
>
>Those screws are also excellent for screwing 4x2 cleats to your trailer 
>deck to
>help keep engines from moving around.  I like #10 x 3" long.
>
>I just thought, what the hell, lets say something about ENGINES for a change.
>8-)))
>
>See ya,  Arnie
>
>Quoting Dave Merchant <kosh at ncweb.com>:
>
> > The purpose-made drywall screws are probably more secure than nails,
> > especially for a ceiling.  In the US, they are black oxide coated,
> > coarse thread, trumpet head, available in a wide variety of sizes.
> >
> > They differ from normal flat head screws in that the head is
> > wider compared to the thread diameter to give better support
> > for the plasterboard (US = drywall) without breaking the paper surface.
> >
> > Normally Philips head, they drive easy + fast.
>
>
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Dave Merchant
kosh at nesys.com
nesys_com at ameritech.net
dmerchant at layerzero.com

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