On 29 May, 17:59, robgraham wrote:

The argument on sheer and tensile is cobblers as diameter for diameter
the sheer strength is going to be the same.

I'll take Machinery's Handbook as authoritative here, over someone who
confuses "shear" and "sheer".

The choice is related to whether you can get at both sides of
the joint - if you can then its a bolt - if you can't it's a screw.

That's a question as to whether you're using a loose nut or not, not
what type of fastener you've used.

A bolt (albeit not a coach bolt) can use a fixed nutplate or a tapped
hole and be inserted by rotating the bolt from one side. Conversely a
parallel-threaded screw can have a nut applied to it.