Hi Mark,

On 26 Jul, Mark Pfeifer wrote:
 
> It can???t have been the technique. It???s a nail. You bend it. It has
> to be the batch of nails. Perhaps they were recovered from a fire that
> over-tempered them? Hit by lightning? Cursed to Ba???al by a carpenter
> after he mashed his thumb with an errant hammer blow? 

Could these have been cut masonry nails, which are hardened? Here's an
example from Tremont:

http://store.tremontnail.com/cgi-bin/tremontnail/items?mv_arg=5

I expect they would break if clinched. 

Regards,

Norm
  Madison, WI