Sash Windows - replacement key for restricting bolt

[ahingston]

I am trying to remove a restricting bolt from a sash window. It is recessed in a small hole (too small for long nose pliers) and the end of the bolt itself is square. I assume that I need to get a key of some description that will fit over this square end and allow me to undo the bolt. Most of the keys I can see have a square end that would fit into a square hole, not the other way round as I need.

Any ideas/help gratefully received.

 

[DC77]

Chubb key 8013k or Era key 584-56 are for the most popular locks fitted to sliding sash windows. The Era version is slightly larger than the Chubb. Available from your local locksmith shop. You may need to jiggle the windows about to get the bolt released from the frame.
Post a picture for definitive answer.
DC
Teamlocksmiths.

 

[ahingston]

Thanks for your reply. I managed to get the right key from Timpsons and it looks like it was the Chubb 8103k.