Torx screw?

[patrick j]

"Of course, lots of people don't notice it is a Torx, and use allen keys in it?"

Today I've encountered something which I had thought was an allen screw but it's a bit different so I'm wondering if it is a Torx screw?

The screw looks just like an allen screw except that the bottom of hexagonal hole for the key is not flat but rather looks concave.

Is that a torx screw?

Thank you

[Ian Stirling]

Maybe. Look closely at the profile. An allen key/screw has a true hexagonal profile. Torx has a hexagon with portions of a circle cut out of each face, so you get a "pointy" star-shape.

[Set Square]

Not if it's hexagonal with flat sides. A Torx bit has grooves in the side - a bit like a spline, and the hole in the screw-head is a matching star-like shape.

See

and scroll down to "Types of screw drive" and look at item d.

[Mark A]

While a Security Torx also has a 'nipple' in the centre, requiring a Security Torx driver with a corresponding hole in the end to go over the screw's centre nipple.

Regards

Mark

[patrick j]

On Sun, 17 Apr 2005 22:30:10 +0100, Set Square wrote (in message ):

Thanks to you and Ian for your replies.

I seem to have allen screws after all :)

The web-site you have mentioned has in addition resolved something I used to wonder about - the difference between Pozidriv and Phillips screws.

[Mike Harrison]

Incidentally, you can also get allen screws with security nipples, but these are much less common than security torx (What's the plural of torx - torxen..?)