Replacement uPVC window locking mechanisms. If your window handle turns but the window won't lock, or the handle is stiff or spins, the espag mechanism inside the sash is usually the cause, not the handle.
Which window mechanism do I need?
Espag (espagnolette) mechanism: the locking bar inside the opening sash, driven by the handle's square spindle. It moves cams into keeps on the frame. Available inline or offset, from 250mm to 800mm long.
Keeps: the parts on the frame that the cams lock into.
The espag is the locking rail in the sash edge that the handle spindle drives, moving mushroom cams into keeps around the frame. When the handle turns but the window no longer locks tight, the espag rail or its gearbox has usually worn.
Measure the backset (faceplate to spindle centre — commonly 20mm or 22mm), the overall rail length, and note the cam positions. Many replacement espags are croppable, cutting down to length to suit your sash.
A shootbolt extends rods from the espag gearbox to throw bolts into the top and bottom of the frame — standard on larger sashes and French casements for extra locking points. Replace like for like, matching backset and rod connections.
Either the spindle has sheared (cheap fix — new handle or spindle) or the espag gearbox has stripped internally. Take the handle off: if the spindle turns the mechanism by hand, replace the handle; if not, replace the espag.
