cause they’re doing it wrong. they don’t understand threads.
you could also study machine shop 101, and take a 14 week class or something.
I think the mechanical function of such a feature should determine the correctness.
The only time I’ve ever seen bolt threads spiral on the end, is while looking at some OEM bolts that Ford puts on some of their components.
But there’s really no significant advantage.
They most likely stamp them with some sort of asymmetric die (custom made).
The unique equipment can be expensive and outweigh the cost for normal folk to condone the expense of engineering every nut and bolt that way — imo.
And it’s pretty common for technicians to shorten or size down the length of a bolt or fastener for a job, which would defeat the purpose of said ‘spiral tipped feature.’ And they’re not going to waste their time trying to add it by hand — when they already know how to deburr threads after cutting the length.
Hi,
V5
over at this thread I post where I have got to with this,
here is image and file, I am done on the profile, have drawn the helix , diameter to base of ‘valley’, just need best method of sweeping this around the helix.
