<VV> Mice and schrews

[Smitty]

>
> So what are 1/4"-20... bolts or screws ?I grew up knowing all machine 
> threaded ones (those which accept machined nuts) as bolts and those 
> commonly used on sheet metal (non machined threads or self threading) as 
> screws. Could be wrong but any time and at every place I ask for a bolt 
> (tornillo in my place) they show me what I know as a bolt. Same for screws

> (pijas in my place).Even the numbered nomenclature is different. 1/4"-20 
> means a bolt and #6-1 1/2" means an screw. They don`t sell screws by a 
> measured diameter.Resuming what The Machinery's Handbook, 23 Revised 
> Edition says near the end of  page 1277 , a bolt can accept a nut, an 
> screw can't but, if that bolt is inserted into a machined hole and 
> tightened by it's head, it is an screw.If I understood well, a 1/4"-20 
> fastener is a bolt if used and tightened with a nut but, an screw if 
> inserted on a threaded hole (technically a nut to me) and tightened by the

> head.Concluding...... ?????????
> As you say.... just my 2 pennies.
> Daniel Monasterio
>********************************
Smitty says, this is all very well and good.  WE are getting input of an
official variety that carries somewhat of duo-national weight.  This still
leaves a burning question of great importance.  If a screw is over 1/4 inch
but has no machined threads is it still a screw.  By some peoples theory, if
you screw it into a blind hole , it is a screw?  I have a box of 5/16
fasteners with hex heads on them. I always called them  bolts.  Lag Bolts.
But when I need one I screw it right into a blind hole.  Is it then a lag
screw?  I am becoming incapacitated with indecision..