About this item
The Von Duprin 9857EO and 9957EO are surface vertical rod exit devices that latch in three places simultaneously -a deadlocking center rim bolt, a top surface rod latch, and a bottom surface rod latch. That's what "three-point latching" means in practice: one push of the bar operates all three points at once for egress. When the door closes, all three re-engage automatically.
Both devices are ANSI A156.3 Grade 1, UL listed for panic exit hardware, and designed for all types of single and double doors in commercial and institutional applications. The only physical difference between the two is the external finish of the mechanism case. The 9857 has a smooth case. The 9957 has a grooved case. Mechanically and dimensionally, they're identical.
Why Three-Point Latching?
Standard rim exit devices latch at one point -the center case bolt engages the door jamb and that's it. On wide doors, tall doors, or any door where frame deflection or forced entry is a concern, a single latch point can be compromised by spreading the door frame or lifting at the top corner.
The 9857/9957 closes that vulnerability. The center rim bolt is 3/4-inch throw, deadlocking. The top and bottom surface vertical rod bolts are 5/8-inch throw each, both deadlocking anti-friction. To open the door from outside without operating the push bar, all three latch points would need to be defeated simultaneously. For high-traffic commercial doors in healthcare facilities, schools, government buildings, and institutional settings where door integrity under duress matters, the three-point system is the correct specification.
Part Number Breakdown: 9857 vs 9957
The "EO" suffix means exit only, ANSI Function 01. The device ships field-selectable -EO, DT (dummy trim), and NL (night latch) are all achievable from the same unit. Outside trim for keyed functions is sold separately in the Von Duprin 98/99 Series trim family.
The device is non-handed, meaning it installs on left-hand and right-hand doors without modification. The only exceptions are the SD (special dogging) and SS (signal switch) options, which are handed.
Specifications
Device lengths: 3-foot bar for doors 2'4" to 3' wide. 4-foot bar for doors 2'10" to 4' wide.
Device centerline from finished floor: 39-13/16" (1,011mm).
Center case dimensions: 8" x 2-3/4" x 2-3/8" (203mm x 70mm x 60mm).
Center rim bolt: Deadlocking, 3/4-inch (19mm) throw.
Top and bottom rod bolts: Deadlocking anti-friction, 5/8-inch (16mm) throw each.
Projection: Push bar neutral -3-13/16" (97mm). Push bar depressed -3-1/16" (78mm).
Vertical rods: 1/2-inch square tubing. Standard rods accommodate 7-foot doors -top rod 34-15/16" (887mm), bottom rod 31-1/2" (794mm). Extension rods available in 1-foot and 3-foot increments for doors over 7 feet. One-piece top rod available for 8-foot and 10-foot doors.
Top and bottom latch case dimensions: 4-1/2" x 2-1/8" x 1-1/2".
Door prep: Covers stock hollow metal doors with 86 or 161 cutouts.
Door thickness: Screw pack included for 1-3/4" to 2-1/4" thick metal or wood doors. 325 SNB sex bolts for top and bottom latch attachment.
Bottom door clearance: 1/4-inch (7mm) maximum recommended door undercut.
Certifications: UL listed panic exit hardware. ANSI A156.3 Grade 1. Hurricane-resistant certification available on select configurations.
Dogging Options
Hex key dogging ships standard on all 9857/9957 devices. The hex key inserts into the center case and holds the push bar depressed for free bidirectional passage during business hours. On fire-rated applications, dogging is not permitted.
Cylinder dogging (CD) is available as an upgrade -a key in the outside cylinder controls the dogging position without a separate hex key. The special center case dogging (SD) option provides an alternative dogging interface for applications with specific access control requirements.
Electric and Alarm Options
The 9857/9957 platform supports the full Von Duprin electric options suite. Electric latch retraction (EL) retracts all three latches simultaneously via solenoid for remote or scheduled access control integration. Quiet electric latch retraction (QEL) does the same with significantly reduced operational noise. The LX latchbolt monitor and RX pushpad monitor provide SPDT switch signals to the access control panel for door status monitoring. The ALK alarm exit kit adds an 85-decibel horn that activates on unauthorized opening. For areas where electrical devices are prohibited, the PN pneumatic latch retraction option handles the mechanical link without wiring.
American Locksets has stocked Von Duprin 98/99 Series hardware since 2001.
Trusted Since 2001
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