[modeleng] Re: Allen heads

Hi Jesse.

I'm a Torx hater too. You should see them on cars here in Ontario Canada
where we use a lot of road salt in the winter. After a couple of years,
there's no hope getting them loose. GM had some on their Lumina model
brakes, that had the heads set in counterbores. When the sockets filled with
rust and dirt, no screwdriver would even enter the socket. You couldn't get
vise grip pliers on the head due to the counterbore, or chisel off the head
in the counterbore, so you were euchred. I've seen more than one such car
get the brake calipers cut off with a torch because of this. Unbelievable,
especially since up to the 1980's they had a simple hex head bolt set that
you could remove no matter what.

In the 1980's Camcar Textron had a large sales force going out into
factories' engineering departments to get the Torx fasteners spec'd into
products while they were being designed. The sales pitch at the time (I was
in such a department at Honeywell, and heard it many times ) was faster
driving on the line and longer bit life, even though the screws and driver
were more expensive than others. There was also lots of design engineering
talk and slide shows about driver areas being larger for applying torque,
more even stress in the head, all kinds of fancy engineering reasons for
switching over. In practice, any screw we used was much stronger than they
needed to be for what we were doing, and we had good threads in the parts,
so torque wasn't a problem to begin with.Well, after a while the screw price
and driver price started going steadily up, the incoming quality consistency
was bad with many soft screws and bad threads, and believe it or not, they
were NOT faster to drive than philips head. As far as longer bit life, we
were getting 6 months out of the philips bits we were using before anyway,
and they cost 40 or 50 cents for the very best ones. The 1 or 2 dollar Torx
ones lasted maybe 8 months if they didn't break or chip in the first hour. I
will say that any that did break early, Textron would replace at no charge,
but they didn't cover our "line down" expenses when the drivers broke.
Totally false economy but the managers wanted to get a "modern" fastener in
use, and fell for the sales pitch.  The problem was, once we changed over
the designs to spec in Torx screws, and changed the ordering system, line
tooling, servicemen's toolkits etc to use them, it was a huge task and very
expensive to go back to philips. Eventually I believe the cost just got too
high and they did go back to philips screws.

Cheers Jeff Dayman Waterloo Ontario Canada


----- Original Message ----- 
From: "Jesse Livingston" <fernj1@xxxxxxxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Tuesday, January 23, 2007 7:43 AM
Subject: [modeleng] Re: Allen heads


> John,
>
> I don't know who came up with the stupid TorX bolt head, but it seemed to
> first appear on General Motors products over here.  I don't wish the
> inventor any harm and I hope he had a full and wonderful life, but died
just
> before he was able to design the thing!  I feel the same way about the
> Phillips head screw designer.  Yeah I know both fasteners were designed
for
> assembly by electric or air powered production screwdrivers, but I still
> despise them.
>
> Jesse the Redneck from Tennessee
>
>  Hi to all,
>  While on the subject of fixings,Does anyone know when TorX started to be
> used.
>
>  there seems more and more way of bolting and screwing and the head shapes
> are always changing, all electrical goods coming in from the far east with
> that screw we don't seem to have a tool to undo it so that we can repair
> it(built in obsolesance!!!)
>
>  yours John Burridge
>
> MODEL ENGINEERING DISCUSSION LIST.
>
> To UNSUBSCRIBE from this list, send a blank email to,
> modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject
line.
>

MODEL ENGINEERING DISCUSSION LIST.

To UNSUBSCRIBE from this list, send a blank email to, 
modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.

Other related posts: