Fastener choice and why...

[AEAdam]

Automotive fasteners are chosen for strength, then cost and weight. Head types are all about (cost, weight) and installation cost. Torx are easy to install with robots. Torx tools also last a long time in a factory.

Maintenance is something auto manufacturers try to take into account, but they sure aren’t thinking about weekend mechanics. More, if they have to provide special tools or training to their dealerships.

 

[peejay75]

JIS should have a dot.

No JIS dot/marking (i think), thanks for the tip @JradM



However, the fact that it could've been JIS (and I currently don't own any JIS tools!), would seem to be all the more reason (for me, to stick it to 'em!) to switch to a different head type...but there's more...a "quick" interwebs search, and it may be that the "perfect" fastener is the one I already own, wonk wonk...oh, the fastener is M6x1.00x(22, threads only; 24, with dog point).

 

[peejay75]

Looks Japanese. Get yourself a JIS screwdriver, it will be an epiphany.

I'll see what I can find!

 

[finn]

This longer unthreaded tip seems to be very common on automotive fasteners, but I haven’t noticed anywhere else (not a thing on mil/aero spec fasteners for example). My theory is it’s one of the few industries that gets fasteners actually manufactured for them to their spec, and the long lead-in helps ease assembly and reduce the risk of cross-threading for high-rate assembly.

Agree that there is no value in trying to find a replacement with this feature.

Most automotive fasteners are designed for automated assembly tools.

There is an interesting YouTube video about the history and pros /cons of Phillips head and Robertson (square ) head screws. One of the points of interest was that Henry Ford wanted exclusive use of Robertson screws in his factor to simplify assembly, but the patent holder refused to negotiate with Ford . Thus, the Robertson didn’t really make inroads in the US. The Phillips was popularized after the war, despite its deficiencies, ie propensity to cam out. The cam out propensity was sold as a feature. Phillips was an advance over traditional straight slot screws for ease of assembly. Straight slot screws are pretty obsolete these days.
Torx, a later development pretty much dominates now because, in part, it doesn’t tend to cam out and has good bit retention with automated assembly tools.

My whole point of bringing this all up is that most fastener design and selection is driven by assembly and ease of automation. Aesthetics come in to play for exposed fasteners in consumer goods.

Allen head screws are still used in industrial settings, but I imagine torx is displacing then, as I doubt the Allen head offers any value over the increasingly common torx variants.

 

[peejay75]

Most automotive fasteners are designed for automated assembly tools.

There is an interesting YouTube video about the history and pros /cons of Phillips head and Robertson (square ) head screws. One of the points of interest was that Henry Ford wanted exclusive use of Robertson screws in his factor to simplify assembly, but the patent holder refused to negotiate with Ford . Thus, the Robertson didn’t really make inroads in the US. The Phillips was popularized after the war, despite its deficiencies, ie propensity to cam out. The cam out propensity was sold as a feature. Phillips was an advance over traditional straight slot screws for ease of assembly. Straight slot screws are pretty obsolete these days.
Torx, a later development pretty much dominates now because, in part, it doesn’t tend to cam out and has good bit retention with automated assembly tools.

My whole point of bringing this all up is that most fastener design and selection is driven by assembly and ease of automation. Aesthetics come in to play for exposed fasteners in consumer goods.

Allen head screws are still used in industrial settings, but I imagine torx is displacing then, as I doubt the Allen head offers any value over the increasingly common torx variants.

Excellent information, thank you!