In days of old, lead was used in masonry to hold screws (now they use plastic).  these were called screw anchors.  from your description it sounds like your railing was not screwed into the wall.  I would still think "anchor" is an appropriate term for the lead holding the railing.

-------------- Original message -------------- 
From: geoff carver <[log in to unmask]> 

> anyone out there up on construction terms? 
> 
> ----- Original Message ----- 
> From: "REYNOLDS, Trevor" 
> To: 
> Sent: Tuesday, June 27, 2006 12:15 PM 
> Subject: [FISH] Looking for an object name 
> 
> 
> Dear all 
> 
> We are trying to work out what we should call the piece of lead that 
> secures a piece of architectural iron work (such as an iron railing) 
> into a socket in a piece of masonry. My best attempt so far is "masonry 
> socket fill" which is not very elegant. Do any of you have any better 
> suggestions, or indeed do you know of an existing name for this? 
> 
> Trevor Reynolds 
> Collections Registrar 
> English Heritage 3 Bunhill Row, London EC1Y 8YZ 
> postal address English Heritage 1 Waterhouse Square, 138 Holborn, London 
> EC1N 2ST