Re: Bolt shear strength

Ken&Laura Chaddock <[EMAIL PROTECTED]> wrote:
> > "Jeff Finlayson" <[EMAIL PROTECTED]> wrote

> >>Aerospace fastener specs (NAS, MS, ..) refer to fasteners with unthreaded
> >>shanks as bolts and fully threaded fasteners as screws.
> 
>       That's misleading because, while many bolts *do* have an unthreaded 
> shank, the fact of an unthreaded shank does not make it a bolt. 

Not misleading.   The fact is aerospace fastener specs refer to 
fully threaded fastners as screws and fasteners with unthreaded shanks 
as bolts.  Applications for both types of fasteners can overlap.  

> The  reason for the unthreaded shank is because the bolt is intended to go 
> into a clear hole and have the nut apply the holding load from the other 
> side so there is no need for threads, where as a screw is intended to 
> draw down against it's own head and if there were an unthreaded shank it 
> couldn't be tightened up against the piece it is intended to hold 
> (unless there were washers or some such).

The heads on screws and bolts are both under compression for preloaded 
joints.  You are correct as far as moving parts and applying torque.