On Sat, 23 Sep 2017 14:05:18 -0400, Ed wrote:

I *really* wish your definition of bolts and screws was true but the standard naming convention is "screwed" up.* ;-)

https://www.mcmaster.com/#screws/=19iejis

https://www.mscdirect.com/browse/Fas...navid=12108710

https://www.fastenal.com/products?r=...eners%22 %7C~

Personally, I use bolt when it's threaded into something that has matching
threads (these are generally relatively shallow angle threads).

I use screws for when it's a steeper-angled thread that "bites" into the
material (often with a sharp point).

Bolts generally have hex heads (for sockets) but not always.
Screws generally have screwdriver notches but not always.

The difference is, to me, in two things mainly:
.. The angle of the threads (screw threads are steeper)
.. The mating material (screws make their own mating threads)

I might be wrong though as I don't follow the McMaster definition exactly.