- cross-posted to:
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- cross-posted to:
- [email protected]
A New York-bound Virgin Atlantic flight was canceled just moments before takeoff last week when an alarmed passenger said he spotted several screws missing from the plane’s wing.
A New York-bound Virgin Atlantic flight was canceled just moments before takeoff last week when an alarmed passenger said he spotted several screws missing from the plane’s wing.
Interestingly enough they are not Phillips it is a very similar looking standard called Torq-set. The lines of the cross are off set a little which make it much easier to put a higher torque into them.
https://en.m.wikipedia.org/wiki/List_of_screw_drives#/media/File%3AScrew_Head_-_Torq-set.svg
Is there any advantage to those over square (Robertson)? I still see 4 contact points when applying torque. So about on par with square and inferior to 6-lobed torx.
Well… It comes down to what material is used, as well as requirements and geometry for the screw.
I love Robertson, but with enough over-torque, you shear the head off the threads or worse, round the hole if there isn’t enough rigid material around the square hole.
Failure modes are: stretching the material outwards until the bit slips. For the torq-set, you would need to shear the screw head material in front of each of the driver’s tips off and out, much less likely than shearing the head off the threads, or shearing the bit itself.
Both have the great feature that screws placed on the head stay in place, making installation much easier.
Aerodynamically, the torq-set has a much smaller ‘opening’ than does Robertson or torx.
Engineering is all about solving a problem in a quality way now, and ideally, considering issues for the future. A downside could be ice/grit getting stuck inside the smaller opening, as an example.