Types of Window Locks and Catches Explained
Window hardware can be confusing because so much of it does a similar job with a different name. Whether you're restoring a period property or simply replacing a worn catch, it helps to know what each fitting is called and which window it belongs on. Here's a plain-spoken guide to the main types.
Casement windows: handles and fasteners
Casement windows are the side-hung (or top-hung) type that swing open like a little door. The hardware that holds them shut and lets you operate them falls into a few familiar groups.
Cockspur handles
The cockspur handle is the classic casement fastener. It's a lever handle that swings down over a wedge-shaped nib on the frame, pulling the window tight against the seal. They're common on aluminium and older timber casements, and they come in different 'nib heights' to suit the gap between sash and frame, so measure yours before replacing.
Casement fasteners and stays
A casement fastener does the same holding job but in a more decorative, traditional form, often paired on period windows with a casement stay, the perforated arm that props the window open at set positions. Stays and fasteners are frequently bought as a matching set for a consistent look.
Sash windows: catches and fasteners
Sliding sash windows, where one or both panels slide vertically, use a different family of hardware because the two sashes meet in the middle rather than swinging open.
Fitch fasteners and Brighton catches
The fitch fastener is the cam-action catch fitted where the two sashes meet. Turning the lever draws the sashes together, tightening the seal and stopping them rattling. The Brighton catch is a screw-action variant that pulls the sashes tight as you turn it, traditionally favoured on Victorian windows. Both improve security by locking the meeting rails together.
Sash stops and lifts
Sash stops are small key-operated bolts that limit how far a sash can be raised, handy for ventilation without leaving a window wide open, and a useful deterrent. To finish the set you'll often want sash lifts (the handles on the bottom rail) and pulls or eyes for the upper sash.
Locking hardware for extra security
Beyond the everyday catches, dedicated window locks add a further layer of security. Key-locking handles, sash stops and locking casement fasteners all resist being forced or reached through a broken pane. If security is your priority, look for locks that are tested to a recognised standard, and remember that a lock is only as good as the screws and frame it's fitted to.
Choosing the right fitting
- Identify your window first. Casement (swings open) or sash (slides up and down) determines the whole family of hardware you need.
- Measure before you buy. Cockspur nib heights and handle spindles vary, so check dimensions against your existing fitting.
- Match the finish. Chrome, brass, black and satin finishes all read differently; buying handles, stays and catches as a set keeps things tidy.
Once you know what you're looking at, replacing tired window hardware is a quick and satisfying upgrade. Explore our full range of window hardware and locks, browse window handles and casement fasteners for swing windows, add matching window stays, and finish the job with the right window accessories. We offer next-day delivery on in-stock orders and free UK delivery over £100.
