Glossary of Terms

Every field of business has a unique language – rolling closures and grilles included. That’s why we’ve included this comprehensive glossary of terms.

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Expressive term used to describe how side-folding curtains operate.

American Disabilities Act requires locking to be accessible within the following height restrictions: 15-inch (381mm) minimum to 48 inch (1220mm) maximum off floor.

Adjustable Chain Stops
A pair of chains fixed to back of pocket and last panel of an EZ Closure. Includes adjustment bolt to tighten or loosen tension of curtain.

Adjustable Height Hardware
Standard on all USPS models to meet strict clearance specifications. Optional on all other models as alternative to fixed height rod/roller panel allowing up to 3/4″ (19mm) upward or downward height adjustment without removal of installed curtain.

Adjustable Lock Rod Stops
Adjusts easily on site within guide to keep bottom bar tightly secured to floor when lock rod is engaged.

Adjusting Wheel
See “Charging Wheel“.

Alignment Bar
An aluminum strip designed to fit into and align two connecting pieces of track.

An electrolytic etched finish forming a hard protective film on the surface of aluminum. Clear, bronze, gold and black are the most common colors.

Anti-Sway Latch
Used exclusively on Roll and Fold partitions. The anti-sway latch locks one panel to another at a 6-inch distance to provide stability when moving partition to and from storage area.

Protective bumper attached to the bottom bar that seals to the floor or counter.

Attached Pull Straps
Straps attached to the top of posts allowing multi-directional movement so curtain can be pulled at the proper angle. Standard on curtains over 9′ (2750mm) high and on all counter applications.

A Mini Roll-Up term. Refers to the barrel assembly of the shutter.


Barrel Assembly
Steel barrel with a drive shaft at one end and a tension shaft on the other. The counterbalance spring assembly is inside the barrel. Rings may be attached to the barrel. Deflection of the barrel may not exceed .03 per foot.

Barrel Rings
Used to raise offset from counterbalance barrel where the top slats of a curtain are attached.

Base Plates
Optional steel plates mounted under the support tubes to help distribute weight of the grille/closure on the floor.

Base Slat
A Mini Roll-Up term. Refers to the bottom bar of the shutter. A base slat contains the locking just as a bottom bar for a grille or closure does. A vinyl astragal on the bottom of the base slat prevents marring of counter tops.

Bell Mouth
Flared upper portion of guides to allow easy entry of the grille/closure curtain.

Between Jamb Mounted
Guides are mounted to wall directly facing into opening and are often in a pack-out configuration. This mounting could require inside charging wheel and fascia.

A curtain that stacks on both sides of an opening and joins together the same as a lead post into a wall channel with an added Lock Rod to prevent sway. Lock Rod engages into floor socket.

Bottom Bar
A heavy-duty aluminum extrusion attached to the bottom of the curtain. Locking is located in the center of the bottom bar. An optional bottom bar plate and/or astragal is often included on the bottom bar. ADA requirements locate locking a minimum of 9-inches off the floor.

Bottom Bar Plate
Mounted to underside of bottom bar for reinforcement and conceals slot in ceiling.

Bracket Plates
Mounted to the support tube or the angle of the guide assembly. Bracket plates support the barrel assembly on the shafts at each end. These plates also support a motor mounting bracket and hood if required. Size of plates determined by height that forms the coil size.


Chain Hoist
A mechanical operator using a continuous hand chain and gear reduction to lift grille/closure. Rarely used in commercial or retail locations.

Chain Stops
A pair of chains fixed to back of pocket and last panel of an EZ Closure. Includes adjustment bolt to tighten or loosen tension of curtain.

Charging Wheel
Winds tension to the counterbalance spring assembly and is locked in place to the outside of a bracket plate with a tension pin.

Clear Opening Width
Side Folding – Refers to width of opening excluding curtain stack/pocket area. Rolling – Actual opening left after the grille/closure is installed. Coil, guides, tubes and angles are not part of the clear opening.

Side folding curtains made of tempered glass; polycarbonate, solid aluminum or perforated steel powder coat painted panels. Rolling curtains made of tempered glass, polycarbonate, solid aluminum and perforated steel slats.

Barrel assembly and curtain in rolled up position.

Coil Box
A Mini Roll-Up term. This represents the counterbalance assembly including a hood and fascia. The terms for Mini Roll-Up’s are known as the axil, end caps, cover face and cover top.

Coil Cord
Electric wire in a tight coil stretching and retracting from the sensing edge on the bottom bar to a junction box located at mid-door height that is wired to the electric operator.

Coil Side
Side of the curtain that the barrel assembly and bracket plates protrude.

Constant Contact
The wiring of a key switch or button activating the electric operator to the open or close cycle only when the key switch or push button control is depressed. The electric motor will stop if pressure is released.

Counter Grille/ Counter Shutter
A grille/closure that is in a location that is not a walk through opening.

Counter Socket
Allows for 1″ (25mm) depth of engagement of the Lock Rod. Constructed of stainless steel, overall dimensions are 1″ x 5/8″ (51mm x 16mm).

Counterbalance Spring Assembly
Located inside the barrel and consists of the torsion spring, spring plugs and tension shaft.

Cover Face
A Mini Roll-Up term. Refers to the coil side and bottom of hood.

Crank Operation
A mechanical operator using an awning or wall mounted gearbox with removable handle.

Cabinet tambour shutter

Side Folding – The completed assembly of side folding panels that make up the side folding closure or grille.

Rolling Grille – Rods and links of aluminum assembled in grille pattern of choice with attached bottom bar.

Rolling Closure – Slats of aluminum assembled with end locks making a door or shutter with attached bottom bar.

Track bent to form 10-inch (254mm) radii of 90, 120, 135 and 150-degree angles. Radii for 90-degree curves for some models are also available in 14″ (356mm) radius. Special curves and radii are available.

Cylinder Locks
Keyed mechanism operating a locking device located on the bottom bar.


Drive Shaft
Fixed to one end of the barrel and requiring a gear/sprocket engaging by chain an electric motor, crank or chain hoist to lift grille/closure.

Dual Pockets
Two EZ or GC built pockets side by side allowing for curtains to stack from the same side covering large expanses.


“E” Guide
Face of wall mounted guide on an angle that faces the opening, usually used on steel jambs.

Electric Safety Edge
Mounted to the underside of the bottom bar, this highly sensitive, electrically actuated device will stop and reverse upon hitting an obstruction.

Electrical Interlock
Prevents motorized operation when bottom bar is locked.

Emergency Egress Door
This is not a pass door. Use is for emergencies only. This 3’0 x 7’0 (900mm x 2020mm) door is built within the curtain. Egress hardware can be thumb turn, latch or paddle device with restrictions to placement on curtain – see your local codes for acceptability.

Emergency Hand Chain/Emergency Hand Crank
Used when the electric motor fails to operate. This is a mechanical means of operating a grille/closure after engaging the emergency disconnect on the electric operator.

Emergency Release
A pull handle that is flush mounted into a wall adjacent to a motorized grille. A simple cable system releases the motor from the drive shaft. The grille is “over sprung” so when the motor is released the grille lifts off the ground for emergency egress. Meets ADA requirements.

End Cap
A Mini Roll-Up term. The shutter’s term for a rolling bracket plate.

End Cap Stud
A Mini Roll-Up term. The studs hold the axle in place from end cap to end cap.

End locks
Fixed on both ends of every other slat to prevent curtain slats from shifting laterally.

Refers to the side of the curtain that is on the Public side.

EZ Closure
Refers to the EZ Grille, EZ Vent and EZ Guard

EZ Grille
Rod/link open-air side folding curtain installed in a 6-inch steel frame pocket with pocket door with magnetic catch.

EZ Guard
Solid aluminum panel side folding curtain installed in a 6-inch steel frame pocket with polymer pocket door with magnetic catch.

EZ Vent
Aluminum perforated panel side folding curtain installed in a 6-inch steel frame pocket with polymer pocket door with magnetic catch.


Door mounting condition where guides
mount directly to the wall, and side clearance is allowed for tension wheel and drive mechanism.

Frequently asked questions

Optional sheet metal cover used when no header is in place and the standard hood leaves exposed the back of the coil.

Fixed Post
Last post of the curtain, closest to wall, that is permanently mounted to wall.

Floor Socket
Allows for 1 1/2″ (38mm) depth of engagement of the lock rod. Constructed of a heavy steel gauge steel outer wall and stainless steel spring loaded head, overall dimensions are 2 5/8″ x 3/4″ (67mm x 19mm).


Curtains made of aluminum rods and links making an “open-air” design.

Side tracks of aluminum or steel that retain the curtain in the opening.


Hand of Operation
Side of the barrel assembly with the drive shaft looking from the coil side.

Hanger Panel Assembly
This is the top section of each curtain panel that contains hanger rod and trolley/roller. These panels along with the post hangers carry the side-folding curtain in the track.

Hanger Rod
This is a rod that is secured to the bottom of a hanger panel and protrudes through the top of the hanger panel an additional 2-5/8 inches. This space forms the distance between the top of the curtain and the bottom of the track and also the stem for the trolley/roller that ride in the track.

Head Plates
See “Bracket Plates

The structural support the track is fastened to that carries the side folding grille or closure.

Header Stop
Aluminum block mounted in pocket adjacent to track on interior so it will catch top stop of travelling end post.

The unobstructed clearance above the clear opening.

Refers to measurement from structural support to finished floor or counter top.

High Cycle Springs
Optional extended life spring assembly for high usage grilles/closures.

Covers the barrel assembly and is supported by the bracket plates and hood supports. Hoods can be made of various materials including galvanized steel, stainless steel, aluminum and vinyl.

Hood Supports
Rigid brackets that fit around the center of the coil, bracing hood to keep its shape and reduce sag.

Hookbolt Lead
Hookbolt lock assembly activated by keyed mortise cylinder or thumb turn interlocking with wall channel.


Refers to the side of the curtain that is on the secured side.

Intermediate Post
A post within a curtain located no more than 10′ (3048mm) O.C. for full height and 6′ (1800mm) O.C. for counter height from any other post. Intermediate Posts should be placed on or near center of curves. Intermediate posts have a lock rod that is spring loaded and unlocked with a keyed cylinder or manually. Lock rods engage into floor or counter sockets.


Key Switch
Key activated electrical control device for electric motors. Motor can be wired for constant or momentary contact operation.


Latch (Lever) Handle
Aluminum spring-loaded lever 1 7/8″ (48mm) used as an alternative to the keyed cylinder, thumb turn or paddle device to secure or unlock lead post or emergency egress door.

Lead Post
The first post of the curtain to pull from the pocket or stacked area. This post will have hook bolt lock that secures into a wall channel or be a top & bottom locking post. Of course, if the curtain biparts, each lead post would be half of the bipart.

Lock Channel
Extruded aluminum channel that accepts bottom bar of tambour shutter and captures hook bolt.

Keyed cylinder operated device mounted in center of extruded bottom bar throws locking bars into guides to prevent lifting of curtain. ADA lock height location available. Simple slide bolts with hasp are available on some models.

Lock Rod
A rod of stainless steel in an intermediate post, top and bottom post and bipart post activated by a spring-loaded cylinder lock or manual pull knob that projects into floor or counter sockets. Rod is adjustable.


Mill Finish
The raw finish of extruded aluminum. Mill aluminum will oxidize if not anodized or painted.

Mini Roll-Up
Compact rolling shutters and doors. Coil size will range about half the size of standard rolling grilles. Ideal for counter applications, cabinets, windows or small full height door areas.

Momentary Contact
Refers to the wiring of a key switch or button that activates the electric operator to the open or close cycle. One a quick turn of the key switch or simple push of a button control is all that is needed. The electric motor will not stop if pressure is released. Almost all commercial and retail applications use constant contact wiring, not momentary contact.

Term often used to describe an electric operator that moves the grille/closure/shutter up and down.

Motor Mounting Bracket
Supports motor from bracket plate or wall on drive shaft side of barrel assembly.

Term used to describe the aluminum extrusions that make up the storefront window frame.


Curtains 9′ and under should be pulled above the halfway point so as not to angle the curtain and cause stress. Higher curtains have attached pull straps, as do all counter height curtains. To close, stand at pocket entrance and slowly feed curtain into pocket. Always pulling or pushing as high as you can.


Pack Off
See “Stand Out

Used for between jamb mounting of guides to provide clearances from obstructions and space for tension shaft and drive shaft.

Paddle Device
Aluminum ‘panic” paddle 4 3/4″ x 3″ (120mm x 80mm) used as an alternative to the keyed cylinder, thumb turn or latch (lever) handle to secure or unlock lead post or emergency egress door.

Generally describes the width and height of material used to make one section that fold. Multiple panels make up the curtain of the grille, closure, door or partition.

Panic Release Device
See “Emergency Release

Pipe Assembly
See “Barrel Assembly

Pneumatic Sensing Edge
A “rubber bumper” with an air system mounted to a bottom bar that will upon hitting an obstruction, signal the electric operator to stop and reverse.

Area inside a wall structure – usually provided by general contractor – to store closure or grille – so it cannot be seen during business hours.


EZ Closure pockets constructed of steel ? inch tubing making a 6-inch wide frame and depths of 15-1/2 inch to 60 inch. Pocket has adjustable height and includes a polymer pocket door with magnetic catch.

Pocket Covering
An option used to cover EZ pockets in lieu of sheetrock. Double-sided tape is adhered to the pockets in the factory. The covering is cut to size and shipped with the EZ Closure. The installer applies the covering to the pocket in the field after the completing the installation.

Impact resistant and flame-retardant thermoplastic, far stronger than acrylic and Plexiglas used for vision panels.

Protection Plate
Attached to the back of a travelling end post, the protection plate is a maximum 10′ (3000mm) in height. This is designed to prevent anyone from reaching around the post. May also be applied to the top and bottom post.

Public Side
Refers to the side of the curtain that is on the Public side.

Push Button Station
Three button control device including open, close and stop, provided with electric operators.


Recessed Lock Plate
Used in lieu of a lock channel, captures hook bolt of bottom bar of tambour shutter.

Removable Soffit
Allows for easy full width access when barrel assembly is mounted above the ceiling.

Retractable Reel
Electric wire in a retractable take up reel from the sensing edge at the bottom bar to a junction box located at mid-door height that is wired to the electric operator.

The process to install a new grille or closure in place of an existing one.

Roller Hinge
A Roll and Fold steel bottom hinge that secures to two panels and has one, two-inch non-marring roller. The hinge provides the partition the ability to move across the floor and to fold open and close.

See “Trolley

Rough Opening
Refers to width of opening including curtain stack/pocket area.


See “Counter Grille/Shutter

Side Folding
A group of security grille and door products that move horizontally from the side of an opening or storefront by means of a track mounted to a supporting header.

Side Rails
A Mini Roll-Up term. Refers to the track the curtain of the shutter glides through upward and down.

Space on either side of opening for support tubes, angles, guides and bracket plates.

An extruded or cold roll-formed continuos profile designed to interlock, fabricating a curtain.
Slide Bolt Lock
Separate hasp type locking units mounted to each side (left/right) of the bottom bar.

Sloped Bottom Bar
An extended bottom bar tapered to match a sloped floor.
Special Curves    Custom curves are bent and hardened in our factory. Note: Limitation of no less than 24-inch radius and 90 degrees.

Spring Counterbalance
See “Counterbalance Spring Assembly

Closure or grille curtain folded tightly forms a stack. Often an area in the wall will be for storage – that space is called a pocket.

Stand Out
The distance from the center of the guide to the closest edge of the bracket plate.

Catch-type obstructions mounted at the top of the guides to prevent the bottom bar from leaving the guides when the curtain is fully raised.

Support Tubes
3″ x 3″ 20′ structural tubular steel, factory drilled and tapped for guides and bracket plates. This self-supporting system allows rolling grilles/closures to mount directly to a concrete slab and ceiling joists.


Take-Up Reel
See “Retracting Wheel

A curtain of slats that move within a cabinet that can be locked. An example of this would be a roll top desk.

Tension Shaft
Located opposite the drive shaft on the barrel assembly. Attached to spring counterbalance assembly and charging wheel to add tension to spring.

Tension Wheel
See “Charging Wheel

Thumb Turn Lock
Thumb turns are required by fire laws in many areas. This non-removable key like knob fixed to a cylinder is used as an alternative to a keyed cylinder. Requires a protective cup and security pattern on grilles to prevent unauthorized entry.

Top & Bottom Locking Post
A lead or end post can be a top & bottom locking post. A spring-loaded drop bolt engages a floor socket and a top lift bolt protrudes into track and header.

Top Cover
A Mini Roll-Up term. Refers to the top of the hood that covers the axle and end caps.

Torsion Spring
A helical wound spring mounted inside the barrel used to counterbalance rolling grilles/closures.

Extruded aluminum 1 3/8″ (35mm) wide by 1 5/8″ (14mm) high. Track is joined together with hardened steel track pins (like model railroad tracks) and alignment bars constructing a smooth continuous surface for the trolleys to carry the curtain.

Traveling End Post
Last post of the curtain that travels to the front of the pocket when curtain is extended across opening. The posts top stop self locks into a header stopper and a floor “V” stop inside of pocket. A full height (maximum 10′ (3000mm)) Protection Plate is attached to back of the traveling end post.

Dual 1 1/8″ (28mm) nylon wheels spaced to ride in track. The trolleys support the full weight of the curtain. (Also refereed to as Rollers)


“V” Stop
Used in pockets only. This “V” shaped piece of steel is spread the width of the pocket and secured to floor. Placement in the pocket is located by fully assembled curtain being stretched into pocket. The traveling end post has a stopper that adjusts down so that only the back post will engage into the 3/4″ high “V” Stop. Counter “V” stop is 1/2″ high.


Wall Channel
A full height extruded piece of aluminum that the lead post fits and locks into. This channel is secured permanently to the wall.

Winding Wheel
See “Charging Wheel

Window Mullion
See “Mullion


“Z” Guide
Face of wall guide mounted on an angle that faces away from the opening usually used on masonry or wood jambs.