Robertson Square Drive

[NW Modeling List]

Well, that is the reality of drywall screws: they are made for a specific application which has low load requirements.  Hence a fairly cheaply made screw intended for light duty and at a low cost.  The sharp point allows easy starting of the screw in drywall or softer woods and the bugle head ‘sucks’ down into the paper on the gyp without tearing the paper.  

 

Phillips head drive is good for power installation applications with a screw feed system which is why they are still used in auto trim.  Slipping out and scratching the interior trim is not common.

 

However, for a high torque drive, they aren’t very good.  TORX, triple square and a whole bunch of other proprietary sockets were invented to overcome the disadvantages of Phillips.  But, they have their issues, too.  Square drive seems to work the best in dirty environments like commercial construction where there a lot of drill chips around.  But, a mismade socket or the wrong taper on the square drive tip can give an installer fits!!!

 

As to LOWES or Home Depot, they carry products for the small remodeler and DIY’er.  And the HVR’s tend to look for inventory turns rather than what makes a good, useful product for productive construction.  The ‘professional’ suppliers have the more productive screws and ones intended for more demanding applications.  

 

Gary Rolih 

 

From: nw-modeling-list-bounces at nwhs.org [mailto:nw-modeling-list-bounces at nwhs.org] On Behalf Of NW Modeling List
Sent: Monday, November 01, 2010 5:58 PM
To: nw-modeling-list at nwhs.org
Subject: Re: Robertson Square Drive

 

I brought this topic up for discussion at a building session this weekend and no one working on the layout could remember stripping or breaking any square drives when building the benchwork. Considering this is a pretty large layout that's a pretty good result. 

I can attest to the fact that Lowes and Home Depot, at least in my area, didn't have much of a selection of square drives, that's how we ended up at McFeely's.  And Gary thanks for reminding me of Fastenal, there is one no more than 3 miles from here that I always forget about. 


Since I use TORX on a daily basis at work I've grown to despise them, now Triple Square Drive or XZN they're awesome, but that's another story. 
                   Doug Langlitz

 

 

-----Original Message-----
From: NW Modeling List <nw-modeling-list at nwhs.org>
To: 'NW Modeling List' <nw-modeling-list at nwhs.org>
Sent: Mon, Nov 1, 2010 12:19 pm
Subject: Robertson Square Drive

Actually, boys, the drywalls screws are the weakest of the screw types in general use.  They are made specifically for the attachment of drywall to wood studs or the thin C-section metal studs used in partition walls.  They also are specified to have a BUGLE head which really only has the volume to hold a Phillips-type socket.  The bugle head is made to ‘sink’ into the paper and gypsum without tearing the paper.  The screws have the minimum of corrosion resistance in the black or gray phosphate coating and they have the lowest strength possible by using a very low alloy steel and a very thin case hardness.

 

The Robertson drives are usually used in screws that require higher strength or more drive torque- the square drive does not cam-out like the Phillips drives do.  McFeely’s sells to mainly wood construction, but there is a whole family of square drive screws used for cold-formed steel construction in load bearing connections- See Grabber or Buildex for some of these screws.  There are some other drive sockets used that are similar to TORX type sockets in these screws.

 

In general, the wood screws with 82 or 90 degree countersink heads will require predrilled and countersunk pilot holes. (Use a combination drill and c’sink.)  Bugle heads in lower density woods like white pine will mostly sink in flush, but will not in yellow pine or fir especially if they have dried out for a while; the wood will be too hard.

 

If you cannot find square drive tips at Lowe’s or Home Depot ( not untypical) go to the ‘professional’ stores especially those aimed at the commercial construction market as commercial construction doesn’t use wood that much, but does use a lot more cold-formed steel and square drive screws.  Look for Fastenal, Grabber, White Cap or HILTI.  Also these guys will have long drive bits used in tools using collated screws ( screws in long plastic strips for feeding automatically) to gain access into cramped quarters.

 

Gary Rolih

A screw guy in Cincinnati

 

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