<VV> 'Hour-glass' head screws?

[Bryan Blackwell]

I've run into them in a couple other places - appliances, I think.

Once you know they're called 'clutch head' finding the correct tool is easy.  They are even available as normal socket or 1/4 hex drive.

https://smile.amazon.com/CTA-Tools-8755-4-Piece-Clutch-Head/dp/B007RKOBOM <https://smile.amazon.com/CTA-Tools-8755-4-Piece-Clutch-Head/dp/B007RKOBOM>

--Bryan

> On Jan 2, 2020, at 9:55 AM, Hugo Miller via VirtualVairs <virtualvairs at corvair.org> wrote:
> 
> I don't think I've ever seen one until I changed the throttle cable on my van. I wonder why GM would have used them? They could just as easily have used a hex-head or a slotted screw. I can't see any practical advantages to the 'hour-glass' slot. And I have certainly never seen a tool for undoing them, so I had to improvise.