Failed Security Bolt on French Window Post your questions and get answers concerning many areas of this subject

[Ascalon]

My French Windows have security bolts fitted to the top and bottom edge of each door. These locks are closed or opened by rotating a brass knob fixed to the escutcheon plate. When unscrewed these plates have a splined rod extending from them. These are quite ordinary and commonplace bolts.
Unfortunately the female inner part of the lock is obviously worn since rotating the knob fails to have any effect. The splined rod shows no wear. Since the door cannot open, one is denied access to its top edge. How can I fix this when I can't get access ?

[Doctor DG]

These are tricky even for a locksmith to open when they fail. One easy way is to use a thin (1mm) metal cutting disc on an angle grinder. Then buy new mortice rack bolts

[Ascalon]

These are tricky even for a locksmith to open when they fail. One easy way is to use a thin (1mm) metal cutting disc on an angle grinder. Then buy new mortice rack bolts

I guess that any method is going to damage the door and frame but your suggestion is likely to be the least destructive and most effective.
Thanks !

[Doctor DG]

There may be some slight marking . It depends how tight the door is fitting the frame. If you can see the bolt going across from the inside and use the thinnest disc you can find it shouldn't be too bad.

[Ascalon]

There may be some slight marking . It depends how tight the door is fitting the frame. If you can see the bolt going across from the inside and use the thinnest disc you can find it shouldn't be too bad.

Sod's law being what it is, it'd be tough to get a razor blade into the joint between the door and frame where the bolt is. Still, your suggestion seems to be the most likely one. Thanks.