Glossary of Windows Hardware Terms
Espag Gear
A multi-point locking mechanism, used on casement windows, that locks the window at multiple points by turning a single handle.
Espag Keep
The stationary part that is mounted on the window frame. The "mushroom" cams on the espag gear latch into the keep to secure the window.
Tilt and Turn Gear
The complex internal mechanism that allows a window to operate in two ways: tilting inward at the top for ventilation or swinging fully inward like a door.
Striker Plate
A metal plate fitted to the window frame. A locking bolt or cam engages with this plate to secure the windows.
Sash Fastener
A catch used to secure the meeting rails of a sash window or to lock a casement window, with both locking and non-locking versions available.
Compression Striker
A type of striker or keep designed to pull the window sash tightly against the frame for a weather-tight seal.
Friction Stay
A hinge with a built-in adjustable friction mechanism that holds a casement window open at a desired position without a separate stay arm.
Easy Clean Hinge
A type of friction stay that allows a casement window sash to slide toward the centre, enabling access for cleaning the outer pane from inside.
Egress Hinge
A safety hinge that allows a window to open to a full 90-degree angle, providing a clear opening for emergency exit.
Restrictor Hinge
A safety hinge that limits how far a window can be opened, commonly used for child safety. It often requires a two-handed action to bypass.
Inline Handle
A window handle design where the spindle is directly in line with the handle's lever. It can be used for both left- and right-handed espag windows.
Offset (or Cranked) Handle
A window handle with a bent or "cranked" lever. The offset provides extra clearance, which can be useful on larger window profiles.
