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Old 11-25-2017, 02:20 AM   #41
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Originally Posted by C lectric View Post
Actually a Square Drive and a real Robertson are not the same.
The Robbie driver has a wee taper for an interference fit with the screw socket. If the screw was well made it will have that same wee taper. Means you can get the screw to stick on the driver similar in manner to a Morse taper but not as determined.
A Square drive screw will not do that. It will fall off.
YOu may not have a choice but I roundly/squarely curse the Square drive. The difference really does make a difference.
EXACTLY!

You and I know this but nobody else seems to. Especially the idiot buyers at the hardware stores that buy that crap square drive.

The two don't mix and the non-taper "square drive" doesn't work near as well as a true Robertson.
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Old 11-25-2017, 02:32 AM   #42
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Regarding the Phillips head screws and the ability to apply sufficient torque... My understanding is that the screw head was designed to use in the automobile manufacturing industry with power drivers, to be easy to engage and to deliver a reasonable amount of torque, but then specifically to pop loose and prevent over-torqueing. Thus the problem with delivering sufficient torque without considerable downward pressure.
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Old 11-25-2017, 02:37 AM   #43
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Wonder how many straight slot screws in near perfect condition are underwater in the mud?

Less than beer cans - I bet! That's how humans are...
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Old 11-25-2017, 03:17 AM   #44
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Quote:
Originally Posted by stonejd View Post
Regarding the Phillips head screws and the ability to apply sufficient torque... My understanding is that the screw head was designed to use in the automobile manufacturing industry with power drivers, to be easy to engage and to deliver a reasonable amount of torque, but then specifically to pop loose and prevent over-torqueing. Thus the problem with delivering sufficient torque without considerable downward pressure.
Yes - they could use a slightly more complicated robotic arm to control the torque but that would cost a few extra dollars. So instead, the rest of the world has to put up with a screw that is poorly designed for what they want to do.

Sometimes capitalism and the free market doesn't quite get it right.
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Old 11-25-2017, 06:54 AM   #45
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Most Excellent discussion every one!

THE one thing I've found (of which I am most guilty) is NOT drilling a large enough pilot hole. For example, when drilling a pilot hole into a fiberglass stringer, you must drill the hole deep enough to cover the depth of the screw AND the diameter must be larger than the inter diameter of the screw body. Most of all screws I have ever striped were due to a pilot hole not deep or large enough. Fiberglass is harder than we think it is and the old screw gun is NOT going to force that screw into solid fiberglass, hence the "Oh S** when you know you tried to put a screw into too small a hole and at that point any screw head type might be subject to damage. That's my story anyway.

Dave
And another thing that I'm sometimes guilty of is not making a small divot to the drilled screw hole with a countersink bit when fastening in fiberglass. You'll notice the high-end manufactures & boat repair operations take that extra step. It stops the gelcoat from cracking when the screw is torqued plus does allows the caulking to do a better job of sealing.
***EDIT!*** I see dhmeissner already brought this up! As usual I'm a day late...
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Old 11-25-2017, 07:04 AM   #46
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The Phillips head was created to strip out!

AS I understand it, after WWII there were vast savings from rationing , nothing to buy and cashing in war bonds.

This drove consumer demand for boats like Chris Craft.

These were wood and required skilled craftsmen to assemble.

The slotted screw heads (and lack of craftsmen) caused lots of damage to expensive pre- built parts like transoms when being installed.

The Phillips was easier to center and drive and would tear out the drive cuts before breaking.

Torx has the most surface area for driving , but SS is still weak , so either predrilling with a proper wood screw drill bit or running a steel screw in first , then replacing works best in real hardwoods.
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Old 11-25-2017, 08:49 AM   #47
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For you Robertson fans who want to splurge a little and be pretty much set for life:

Part Specials | Sam's Marine International
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Old 11-25-2017, 09:02 AM   #48
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For removal after becoming covered with paint, varnish, caulking, glue under plugs, and so on; you can't beat an old fashion slotted head screw and a sharp proper sized common screw driver.
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Old 11-25-2017, 09:14 AM   #49
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Originally Posted by caltexflanc View Post
For you Robertson fans who want to splurge a little and be pretty much set for life:

Part Specials | Sam's Marine International
Nearly 50 each, in a bulk variety pack!

Surely if you know what sizes you want there are cheaper suppliers of 100 at a time?
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Old 11-25-2017, 10:15 AM   #50
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Greetings,
Mr. 61. Re: post #49. My thoughts exactly. We had a "home port" near Elizabeth City NC for some period of time and I was easily able to source my preferred screws from the local Fastenall outlet. Granted, they did not have them in stock so ordering was necessary but I don't recall having to wait an inordinate amount of time for delivery.
I was not aware of the engineering differences between Robertson and "square socket" fasteners so maybe I was, in fact, using squares as opposed to "Robbies". Still, far better than the cursed Phillips.

A story I heard many years ago was that Robertson, refused to license manufacture of the design to Henry Ford a fact borne by the Wiki article.
https://en.wikipedia.org/wiki/P._L._Robertson
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Old 11-25-2017, 10:35 AM   #51
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Robertson, Canadian, Hatteras, Square Head...sameo-sameo. My boat is built with them and I am glad.
Actually not.

Robertson was too smart by half. Robertson, though the best, but due to patents, didn't catch on in the US or in Europe. In the US, someone thought to beat the patent by inventing the "Square" drive. It is good but the sides of the square are more vertical than Robertson, so not quite as good. I have not heard of any called "Canadian" but it seem evident that the reference is to Robertson. Hattereas, likewise to "Square".

FWIW My boat's path has been littered with slot screws. I do not re-use either slot or Phillips. A get to fail the float test and get replaced with Robertsons.

On my recent trip to visit my Daughter and family in Portugal, I encountered the European standard, Phillips only. No others to be found in Portugal.
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Old 11-25-2017, 11:36 AM   #52
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I guess Huey Lewis was right: "It's hip to be square!"
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Old 11-25-2017, 01:19 PM   #53
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Our Campion being Canadian is 99% Robertson, which is good. I do like the Torx but I am happy with most everything being Robertson on the boat.

Fred P............
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Old 11-25-2017, 02:01 PM   #54
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I first encountered Robertson (AKA 'square' to uneducated Yankees) drive when I went to McGill in 1966. Whenever I encountered one I deep-sixed it and put in a Phillips. I associated 'em with cheap furniture. When we got our '72 Morgan 27, all the concealed screws were square (or Robertson) and all the exposed were Phillips. Typically, the concealed screws were painted or gel-coated over by the factory. I learned to deal with them, reuse them, but only on the Morgan.

I first encountered Torx fasteners while working on cars in the late '60s. They were typically used for metal trim affixed to body sheet metal. Of course they were steel, and corrosion rendered them impossible to remove.

All my work on antique house hardware, old furniture, and on antique musical instruments involve slotted screws. Interestingly, screws used on finer things have narrower slots. I'm forever regrinding screwdrivers to get them to fit w/o buggering the heads. At least, you can take a hammer and a screwdriver and clean the paint out of a slot!

Adequately cleaning a Torx, Robertson or square is pretty fraught with frustration.

When restoring/reassembling, I use the design as necessary to match the rest in the application. Nothing is more annoying than to find oneself in position with an appropriate screwdriver and find that the PO used a mismatched fastener! But, I've taken to tossing any damaged fastener, even if I've just put it in.
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Old 11-25-2017, 02:44 PM   #55
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Just for giggles I checked my bit box and checked the square drives with calipers. All were tapered, mostly about 0.020" from tip to end of flats. But they were not consistent!! Varied about 0.010" from smallest to largest. Cheap crap I guess.

So how much taper is supposed to be on Robertson?
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Old 11-25-2017, 02:45 PM   #56
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I can't wait for square drive to become predominant. It's all I buy for drywall/deck screws. Canadians know the proper name, but it won't come to mind at present.
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Old 11-25-2017, 02:46 PM   #57
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Also have a lot of SS FHSMS in square drive.
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Old 11-25-2017, 03:30 PM   #58
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Quote:
Originally Posted by koliver View Post
On my recent trip to visit my Daughter and family in Portugal, I encountered the European standard, Phillips only. No others to be found in Portugal.
I think what they have in Portugal and most of Europe are Pozi-drive, rather than Phillips. They look similar, but Pozi-drive are far superior.
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Old 11-25-2017, 05:32 PM   #59
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Robbies rule! One of the good things about my BC-built boat. Wish they were easier to find locally. Will talk to Santa about a Robertson screw kit.
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Old 11-25-2017, 06:28 PM   #60
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Just for giggles I checked my bit box and checked the square drives with calipers. All were tapered, mostly about 0.020" from tip to end of flats. But they were not consistent!! Varied about 0.010" from smallest to largest. Cheap crap I guess.

So how much taper is supposed to be on Robertson?
I did the same thing but didn't measure. Not all are tapered. I have ones that are marked S1, S2, R3 and ones with no markings. Is there standard?
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