ISO 21174:2026

International
Standard
ISO 21174
First edition
Doors, windows and curtain
2026-03
walling — Hardware for doors and
windows — Vocabulary
Portes, fenêtres et façades-rideaux — Quincaillerie pour portes et
fenêtres — Vocabulaire
Reference number
© ISO 2026
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Generic hardware .1
3.2 Operating element .3
3.2.1 Operating element for window .3
3.2.2 Operating element for door . .4
3.3 Fastening element .6
3.3.1 Fastening element for window.6
3.3.2 Fastening element for door .7
3.4 Supporting element .11
3.5 Hold-open and controlling element . 12
3.5.1 Hold-open and controlling element for window . 12
3.5.2 Hold-open and controlling element for door . 13
3.6 Hardware for specific window and door system . 15
3.6.1 Projecting reversible window hardware . 15
3.6.2 Slide-only, sliding and folding, lift and slide window hardware .16
3.6.3 Tilt and turn window hardware .16
3.6.4 Sliding door and folding door hardware .16
3.6.5 Panic and emergency exit hardware .18
3.6.6 Unframe glass doorset hardware .19
3.6.7 Miscellaneous .19
Annex A (informative) Illustration of the various defined terms .20

iii
Foreword
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Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
For ease of use, terms and definitions are divided into 6 categories as follows:
— subclause 3.1 generic hardware - refers to hardware products or components or expressions commonly
used in the window and door market or industry;
— subclause 3.2 operating element - refers to components, operated by hand or electronic driving, used
to open, close and/or lock door leaf or window casement/sash directly or by driving the transmission
mechanism to do so, e.g. fixed handle, lever handle, knob;
— subclause 3.3 fastening element - refers to components that prevent the relative displacement between
the door leaf or window casement/sash and the surrounding frame in a closed position, e.g. espagnolette,
lock;
— subclause 3.4 supporting element - refers to component that connects door leaf or window casement/
sash to their surrounding frame and bears the door leaf or window casement/sash, e.g. hinge, roller.
Usually, they will be designed to bear the dead-load required for the acceptable operation of the door leaf
or window casement/ sash, and
— subclause 3.5 hold-open and controlling element, - refers to components that can limit the opening angle
of door leaf and window casement/sash relative to their frame, e.g. limiting restrictor, and/or allow
the door leaf and window casement/sash to be retained in a specific position, e.g. safety restrictor or
hold open device, and/or return the door leaf and window casement/sash to a closed position e.g. door
closing device, and/or drive the door leaf and window casement/sash open electronically e.g. swing door
operator;
— subclause 3.6 hardware for specific window and door systems - refers to those used particularly in/on
certain window and door systems.
Illustrative figures for the terms are given in the Annex A.

v
International Standard ISO 21174:2026(en)
Doors, windows and curtain walling — Hardware for doors
and windows — Vocabulary
1 Scope
This document defines terms relating to hardware used in windows and pedestrian doors.
This document mainly defines terms for hardware used for the connection between window sash/casement,
door leaf and their corresponding frames, as well as the hardware used for operating the window sash/
casement and door leaf.
This document does not define terms for fixing elements used as a means of connecting the hardware to the
door and window sash/casement profile or frame, nor for hardware used for connection between the door/
window frame and their openings, such as screws, bolts, etc.
This document does not give physical definitions related to performance requirements and associated test
methods of the hardware.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Generic hardware
3.1.1
backset
horizontal distance measured from the outside face of the lock to the centreline of the hole of the spindle
(3.1.15)
Note 1 to entry: See Figure A.10 and Figure A.16
3.1.2
building hardware
component of doors, windows, hatches and similar construction products to provide them with a specified
function, mainly opening and closing, locking, fixation and sealing
3.1.3
door fitting
items of building hardware (3.1.2) to be fitted to a door
3.1.4
fastener
component used to open, close, and secure a door, window, shutter, or gate

3.1.5
fastening
fixing of one component of a building element to another
3.1.6
fittings
small components, other than fasteners (3.1.4), fixed to a primary component for a specific purpose
3.1.7
handle
operating device, where applicable with locking mechanism, with which the window/door hardware can be
mechanically operated
3.1.7.1
flush handle
recessed handle (3.1.7) that sits flush with the surface of the sash or door leaf
Note 1 to entry: Also known as recessed pulls or flush pulls (3.2.2.10).
3.1.7.2
window handle
operating mechanism with which the window hardware can be mechanically operated to open and close the
window
Note 1 to entry: See Figure A.1, Figure A.2 and Figure A.3.
3.1.8
hinge
device used for connecting the door/window frame and its leaf/casement, supporting and rotating the door
leaf and window casement on a fixed axis for opening
Note 1 to entry: See Figure A.20, Figure A.21, Figure A.22, Figure A.23, Figure A.24, Figure A.25, Figure A.26,
Figure A.27, Figure A.28, Figure A.30, and Figure A.44.
3.1.9
latch
self-engaging fastener (3.1.4) which restrains a movable component (e.g. door leaf) in a closed position and
which can be released
Note 1 to entry: See Figure A.15.
3.1.10
lever handle
rotatable operating element designed as a lever which engages a spindle (3.1.15) passing through a window
or a door
Note 1 to entry: See Figure A.1, Figure A.2, Figure A.3, Figure A.4, and Figure A.5.
3.1.11
lock
fastener (3.1.4) which secures a movable component in a closed position within a door frame and which is
operated by a key (3.1.12) or other device
Note 1 to entry: See Figure A.14, Figure A.15, Figure A.16 and Figure A.18.
3.1.12
key
device that is removable and portable and is used to operate the lock (3.1.11)
Note 1 to entry: See Figure A.1, Figure A.2, Figure A.3, Figure A.14, Figure A.15, and Figure A.16.

3.1.13
window fittings
window furniture
items of building hardware (3.1.2) to be fitted to a window
3.1.14
safety device
component for doors and windows which is intended to prevent injuries and protect users of a building
3.1.15
spindle
connecting element to transfer the torque from the handle (3.1.7) to the rotatable part of lock (3.1.11)
Note 1 to entry: See Figure A.2, Figure A.4 and Figure A.6.
Note 2 to entry: Square spindles are very common, but other shaped spindles are also permissible.
3.2 Operating element
3.2.1 Operating element for window
3.2.1.1
connector
fork
connecting element to transfer the torque from the geared-handle (3.2.1.3) to the slideable part of the
window espagnolette (3.3.1.2)
Note 1 to entry: See Figure A.1.
Note 2 to entry: Otherwise known as engaging piece, tongue or slider
3.2.1.2
click mechanism
assembly of components to position the handle (3.1.7) in the defined click positions with the tilt& turn
hardware’s operation positions
Note 1 to entry: See Figure A.1 and Figure A.2.
3.2.1.3
geared-handle
operating mechanism with which the window hardware can be mechanically operated and connector
(3.2.1.1) that serves as the connecting element
Note 1 to entry: See Figure A.1.
3.2.1.4
key-operated locking mechanism
assembly of components for securing the hardware's set position, enabling the further operation only with
appropriate means (e.g. a key (3.1.12))
Note 1 to entry: See Figure A.1, Figure A.2 and Figure A.3.
3.2.1.5
key-operated lockable hardware
component for securing the hardware's set position, enabling the further operation only with appropriate
means (e.g. a key (3.1.12))
3.2.1.6
non-key-operated locking mechanism
assembly of components for securing the handle's (3.1.7) set position, enabling the further operation without
appropriate means
Note 1 to entry: Examples of non-key-operated locking mechanisms include designs with deactivation of the locking
mechanism via "push-to-open", button- or thumb-operation.
3.2.1.7
non-key-operated locking hardware
component, which can be locked and/or unlocked without the use of a key (3.1.12)
Note 1 to entry: An example of non-key-operated locking hardware is a PTO (push to open) window handle (3.1.7.2).
3.2.1.8
non-lockable hardware
component for securing the hardware's set position without appropriate means (e.g. a key (3.1.12))
3.2.1.9
rosette
screw-fixed base body located on the window profile that serves as a rotatable window handle
(3.1.7.2) mounting
Note 1 to entry: See Figure A.1, Figure A.2 and Figure A.3.
3.2.1.10
window crank handle
component used to manually open the casement by rotating the handle (3.1.7)
3.2.1.11
window fastener handle
operating device where applicable with releasable and/ or locking mechanism, to hold the window in a
closed position
Note 1 to entry: See Figure A.3.
Note 2 to entry: Also known as Cockspur handles.
3.2.2 Operating element for door
3.2.2.1
backplate
element generally, but not essentially, rectangular in plan whose purpose is, firstly, functional, providing a
bearing for the rotation of a door lever handle (3.1.10) or knob (3.2.2.4) and the means of attachment to the
door; and, secondly, decorative, working as a trim plate (3.2.2.17) to cover holes provided in the door for the
passage of spindles (3.1.15), keys (3.1.12) or lock cylinders (3.3.2.7)
Note 1 to entry: See Figure A.4 and Figure A.5.
3.2.2.2
baseplate
element generally, but not essentially, rectangular in plan whose purpose is, firstly, functional, providing a
bearing for the rotation of a door lever handle (3.1.10) or knob (3.2.2.4) and the means of attachment to the
door; and secondly, decorative, working as a trim plate (3.2.2.17) to cover holes provided in the door for the
passage of spindles (3.1.15), keys (3.1.12) or lock cylinders (3.3.2.7)
Note 1 to entry: See Figure A.4.

3.2.2.3
bow handle
pull for use on heavy doors
Note 1 to entry: See Figure A.7.
3.2.2.4
door knob
fixed or rotatable operating elements wherein:
a) the rotatable element will usually engage a spindle (3.1.15) passing through the door and operate the
latch mechanism when rotated, so that the latch bolt (3.3.2.19) is withdrawn to unlatch the door; and
b) the fixed element is used to pull the door open or push the door closed
Note 1 to entry: See Figure A.6 and Figure A.15.
3.2.2.5
emergency release
facility provided on the external plate (3.2.2.8) that enables the door to be opened in case of emergency
Note 1 to entry: See Figure A.5.
3.2.2.6
entrance set
set with a lever handle (3.1.10) on the one side of the door and e.g. a door knob (3.2.2.4) or bar on the other
3.2.2.7
escutcheon
surround with a shaped hole to accommodate a key (3.1.12) or a lock cylinder (3.3.2.7), with or without a
pivoted cover plate intended primarily to protect the door leaf from abrasion caused by keys (3.1.12)
Note 1 to entry: See Figure A.6.
3.2.2.8
external plate
backplate (3.2.2.1) or rose (3.2.2.18) that is fitted on the external face of a door
Note 1 to entry: See Figure A.4, Figure A.5 and Figure A.6.
3.2.2.9
fixed handle
handle (3.1.7) which is fixed against rotation and is used to pull the door to the open or closed position
3.2.2.10
flush pull
fitting (3.1.6) providing a recessed finger hold for sideways or pulling movement
3.2.2.11
half set
single lever handle (3.1.10) or knob (3.2.2.4) attached to a plate or rose (3.2.2.18) which enables operation of
the lock (3.1.11) or latch (3.1.9) from one side of the door only
3.2.2.12
indicator
device that is visible from the exterior of the door to indicate whether the door is locked or unlocked
3.2.2.13
internal plate
backplate (3.2.2.1) or rose (3.2.2.18) that is fitted on the internal face of a door
Note 1 to entry: See Figure A.5.

3.2.2.14
latchplate
backplate (3.2.2.1) adapted for use with a latch (3.1.9) and having no keyhole or cylinder aperture
3.2.2.15
lockplate
backplate (3.2.2.1) having an aperture for use with a cylinder (3.3.2.7) or lever key (3.1.12)
Note 1 to entry: See Figure A.4.
3.2.2.16
pull handle
fixed handle (3.2.2.9) mounted on a door leaf providing a means to open and close a door leaf by hand
Note 1 to entry: See Figure A.8.
3.2.2.17
trim plate
component of an assembly of two parts that fit together to form a backplate (3.2.2.1) or rose (3.2.2.18) which
is fastened to baseplate (3.2.2.2) as a decorative cover
Note 1 to entry: See Figure A.4 and Figure A.6.
3.2.2.18
rose
element generally circular, but which may have equi-axial or approximately equi-axial shapes such as square
or octagonal, that otherwise has the same features as a backplate (3.2.2.1)
Note 1 to entry: See Figure A.6.
3.2.2.19
set of door furniture
two lever handles (3.1.10) or knobs (3.2.2.4) with two lockplates (3.2.2.15) or latchplates (3.2.2.14) (or,
alternatively, roses (3.2.2.18) and escutcheons (3.2.2.7)), complete with a spindle (3.1.15) and fastening
elements to operate the latch (3.1.9)
Note 1 to entry: See Figure A.4, . Figure A.5 and Figure A.6
3.2.2.20
thumb turn
small T-handle, knob (3.2.2.4) or other handle (3.1.7) fitted on the internal plate (3.2.2.13) of a set of bathroom
lock furniture (3.2.2.19) that operates a lock deadbolt (3.3.2.11) to provide privacy rather than high security
Note 1 to entry: See Figure A.5.
3.3 Fastening element
3.3.1 Fastening element for window
3.3.1.1
cam keeper
cam keep
component to accept the cam, e.g. mushroom cam (3.3.1.4) or roller cam (3.3.1.5), from the window or door
locking mechanism
Note 1 to entry: See Figure A.9.

3.3.1.2
espagnolette
locking mechanism for windows and door height windows that usually have a maximum handle movement
of 180°
Note 1 to entry: See Figure A.10.
3.3.1.3
finger catches
locking device for windows that can be operated by a finger
Note 1 to entry: See Figure A.11.
3.3.1.4
mushroom cam
component attached to a moving shaft which is mushroom shaped and which engages in the cam keeper
(3.3.1.1) to enable the door/window to be closed
Note 1 to entry: See Figure A.9.
3.3.1.5
roller cam
component attached to a moving shaft which is cylindrical shaped and which engages in the cam keeper
(3.3.1.1) to enable the door/window to be closed
Note 1 to entry: See Figure A.9.
3.3.1.6
sash fastener
device to secure, in the closed position, the sashes of a double or single hung vertically sliding window and
the sashes of a horizontally sliding window
Note 1 to entry: See Figure A.12.
3.3.1.7
roller catch
device with one or more rolling parts which help a door leaf/window casement/sash to be kept in the closed
position
Note 1 to entry: See Figure A.13.
3.3.2 Fastening element for door
3.3.2.1
anti-separation point
locking point (3.3.2.25) designed to prevent the separation of a door leaf from its frame or adjacent door leaf
in the plane of the door
Note 1 to entry: See Figure A.14.
Note 2 to entry: Examples of anti-separation points are hook and mushroom types.
3.3.2.2
bored latch set
fastener (3.1.4) that comprises an integral assembly of door furniture with a tubular latch (3.3.2.39)
Note 1 to entry: See Figure A.15.
3.3.2.3
bored lock set
fastener (3.1.4) that comprises an integral assembly of door furniture with a tubular lock (3.1.11)
Note 1 to entry: See Figure A.15.

3.3.2.4
bolt
device for securing, or helping to secure, a door or window in the closed position, comprising a suitably
guided moving member, operable from the protected side only by hand or foot, either directly using a knob
(3.2.2.4) or slide, or indirectly using a lever/handle (3.1.7) or rack and pinion mechanism
Note 1 to entry: See Figure A.14, Figure A.16, Figure A.45, Figure A.46 and Figure A.47.
3.3.2.5
cam
component of the cylinder (3.3.2.7) to provide the movement to effect locking
Note 1 to entry: See Figure A.17.
3.3.2.6
clenching point
arrangement of components to draw together a door and its frame in the door closing direction to reduce
distortion of the door and/or compress seal (may also be a locking point (3.3.2.25) and/or anti-separation
point (3.3.2.1))
Note 1 to entry: See Figure A.14.
3.3.2.7
cylinder
device, usually distinct from its associated lock (3.1.11) or latch (3.1.9), operated by the key (3.1.12)
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.8
construction key
device which is temporarily used instead of a cylinder (3.3.2.7) during the construction phase of a project
3.3.2.9
cylinder core/plug
cylindrical portion of the cylinder (3.3.2.7), which rotates when the correct key (3.1.12) is used
Note 1 to entry: See Figure A.17.
3.3.2.10
cylinder lock
lock (3.1.11) in which the lock mechanism (3.3.2.23) is operated by one or more cylinders (3.3.2.7)
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.11
deadbolt
movable part of a lock (3.1.11) that usually engages a locking plate (3.3.2.26) and withdraws into a lock case
(3.3.2.23) that is operated at least in one direction by a key (3.1.12), handle (3.1.7) or thumb turn (3.2.2.20)
Note 1 to entry: See Figure A.16.
3.3.2.12
deadlocking
action of moving a bolt (3.3.2.4) to a thrown position where pushing back of the bolt (3.3.2.4) is positively
prevented
3.3.2.13
detaining element
component which is moved by a key (3.1.12) into a pre-determined position to allow the bolt (3.3.2.4) to be
operated
3.3.2.14
differ
variation between lock mechanisms (3.3.2.23) of similar design due to differences in the lift and/or position
of the detaining elements (3.3.2.13)
3.3.2.15
flush bolt
lever or sliding action bolt (3.3.2.4) which usually secures the inactive leaf when mounted does not project
above the surface of the leaf
3.3.2.16
follower
part of a lock (3.1.11) that operates latch bolt (3.3.2.19) and/or deadbolt(s) (3.3.2.11) when turned by a spindle
(3.1.15)
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.17
forend
part of a case through which the lock (3.1.11) is fixed to the door leaf and through which the latch bolt
(3.3.2.19) and/or deadbolt (3.3.2.11) pass
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.18
hook latch bolt
hook-shaped bolt (3.3.2.4) grappling the locking plate (3.3.2.26) to secure a door leaf
Note 1 to entry: See Figure A.14.
3.3.2.19
latch bolt
spring-loaded movable part of a lock (3.1.11) that usually engages a component fixed to a frame, and
withdraws into a lock case (3.3.2.23) that automatically engages a locking plate (3.3.2.26) to keep the door
leaf in its closed position
Note 1 to entry: See Figure A.14, Figure A.16 and Figure A.47.
3.3.2.20
lever lock
lock (3.1.11) with integral differs (3.3.2.14) operated by a key (3.1.12)
3.3.2.21
lock case
part of a lock (3.1.11) in which the lock mechanism (3.3.2.23) is housed
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.22
lockable follower
mechanism operated by a key (3.1.12) to block the rotation of the follower (3.3.2.16) inside a lock case
(3.3.2.21) or the rotation of a handle (3.1.7)/ knob (3.2.2.4) when it is a part of the lock (3.1.11)
Note 1 to entry: See Figure A.14 and Figure A.16.
3.3.2.23
lock mechanism
constituent parts of a lock (3.1.11) that operate the deadbolt (3.3.2.11) and/or latch bolt (3.3.2.19), where
required, providing the differs (3.3.2.14)
Note 1 to entry: See Figure A.14 and Figure A.16.

3.3.2.24
lockin
...