At the GM Board meeting:
"Have we conquered the repair market yet?"
"No, all the mechanics went out and bought torx bits. What do we do now?"
"We'll invent a new, in-between size with a slightly different shape! Then they'll have to bring their trucks to us for repair!"
Every mechanic out there:
"Hmm... this old torx bit kinda fits. I'll just use it."
They're job security bolts. GM, VW, BMW, and every other manufacturer who uses them can kiss my grits. Idiots.
Try working on any British vehicle built up until the mid-'60's.
Jaguars are the worst! They used odd-ball fasteners right up into the '70's.
They used a combination of...
British Standard Whitworth (BSW)
United National Course & Fine. (UNC/UNF)
& Metric.
The 'sizes' of Whitworth wrenches refers to the diameter of the threaded stud, and not the bolt head itself.
A 7/16" wrench fits a 1/4" Whitworth.
A 1/2" fits a 5/16" Whitworth and so on.
Most important is that the threads are different! Pitch/shape/depth.
You can't switch one with the other.
A '73 E-Type has 2 Whitworth screws in the firewall. The only 2 in the whole vehicle! WHyyy???