Screws??

[Mike B]

Hi

I have been chasing around trying to find some stainless screws for attaching some cleats to solid beams. I was looking for the "traditional" style (i.e. screws with a part plain, part threaded shank) screws, but could only find the more "modern" style that is threaded all the way down the shank.

The supplier informed me that they are exactly the same in use and that he rarely gets stock of the "traditional" style anymore. Admittedly, he is more of a trade tool/hardware supplier, but this has made me curious as to whether there is actually a difference and if so what it is.

FWIW I always thought that the plain part of the shank was required in order to allow the screw to turn freely and "pull" the part being attached to what it was being screwed to (as well as fitting in the same size pilot hole)...

But I'm probably wrong, so all thoughts gratefully received...

Cheers
Mike

 

[Noel]

Mike as I'm sure you know the non threaded part of the shank helps to stop bridging as well as assisting in driving the screw. You should get the same result in fully threaded screws by drilling the cleat out to the same bore as the overall thickness of the screw. Indeed this should be done for the half threaded screws too. Then just a normal pilot hole in the receiving timber.
Noel

 

[Mike B]

Noel - thanks.

"Bridging" was what I was referring to but did not explain too well.

Still wondering why modern style screws are threaded all the way up when the traditional ones were not...

Mike

 

[DaveL]

Mike,

Just a guess but power drivers may have some bearing on this?

 

[SketchUp Guru]

I find screws with no shank (unthreaded portion) annoying because you can not use the screw to pull two pieces together tight. Is this what you call 'bridging'?

I have some stainless screws with shanks that I got from an online supplier. Check this link http://www.stainless-fasteners.com/Sharx.htm

You might also have a look at http://jamestowndistributors.com/to;ID; ... less.Steel

Or http://www.hamiltonmarine.com/Findex.html

Make sure you aren't using sheet metal screws because those never have a shank.

 

[Mike B]

Dave R - exactly. Thanks for the links.

Obviously they can be used, but then you have to enlarge the hole in the piece you are attaching to provide the threaded shank clearance, which I find annoying and unnecessary and therefore cannot see why screws are made in this way. Presumably it costs more to produce the "all threaded" versions too...

But there must be a logical explanation somewhere...:?

 

[SketchUp Guru]

You're welcome for the links.

One thing I've also noticed on a number of screws that do have shanks is that the shank is the minor diameter of the threads. I believe this comes from stamping the threads. In the old days of cut threads the shanks were larger. Probably saves the company money.