Adams Rite 1870HM Cylinder-Operated Flushbolt For Hollow Metal Doors- Flat faceplate

The Adams Rite 1870HM is a cylinder-operated flushbolt engineered for greater key control on paired hollow metal doors, preventing unauthorized or accidental locking of the inactive leaf. Unlike conventional flip-lever flushbolts that any staff member or visitor can operate, the 1870HM requires a mortise cylinder key to engage or disengage the bolt. This single innovation matters in schools, hospitals, office buildings, and institutional facilities where only authorized personnel should control access to specific door leaves. Designed for top-and-bottom installation on the inactive leaf of a door pair, the 1870HM works alongside a primary deadlock on the active leaf to deliver a complete security layer. The stainless steel hexagonal bolt features an 11/16" throw, a flat 1" x 8" faceplate, and installs at either threshold or header height.

Why paired doors need separate control on the inactive leaf

A pair of hollow metal doors consists of an active leaf (the one people open and close during normal traffic) and an inactive leaf that stays closed unless both doors need to be opened wide. Building codes and facility workflows require the inactive leaf to remain secured except during full-width egress or equipment movement. Manual or lever-operated flushbolts on the inactive leaf create a vulnerability: any employee, student, or visitor can lift the lever and unlock that door independently. The 1870HM eliminates that risk. By requiring a key to operate, it puts control in the hands of building management. Facility managers can restrict inactive-leaf access to authorized personnel only. This matters in hospital corridors where patient movement must be tracked, in school hallways where unsupervised door access poses safety risks, and in office suites where separate tenant access must be prevented. The key-control model also discourages casual tampering and prevents children or unauthorized people from unintentionally opening both door leaves simultaneously.

How cylinder-operated flushbolts integrate with active-leaf deadlocks

The 1870HM is recommended for paired installation with an Adams Rite MS1850SN deadlock on the active leaf. This configuration creates a coordinated security picture: the primary deadlock controls the main traffic leaf, while the flushbolt controls the secondary leaf. Installing both bolts at the top and bottom of the inactive leaf (a dual installation) provides maximum security on doors with high-traffic or high-risk scenarios. The 360-degree key turn on the 1870HM throws or retracts the stainless steel bolt cleanly, with a positive stop that prevents the key from being removed unless the bolt is fully locked or fully unlocked. This mechanical precision prevents accidentally leaving the door in a mid-position where the seal isn't complete. The bolt uses the same over-center action mechanism as Adams Rite's MS pivoted deadlocks, meaning facilities already familiar with that product line will recognize the operation immediately. Because the cylinder accepts standard 1-5/32" mortise cylinders with MS cam configuration, you can key-match the flushbolt to your primary deadlock, creating a single master key for both devices. Alternatively, you can use different cylinders to segment access by floor, building wing, or user role.

Hollow metal door installation and finish options

The 1870HM is purpose-built for hollow metal construction. The case measures 7/8" x 6" x 1-21/32" in steel with corrosion-resistant plating and accommodates standard 1-1/4" backset (the distance from the door edge centerline to the cylinder center). The stainless steel bolt itself resists rust and discoloration in high-moisture areas like hospitals or coastal facilities. The supplied 2-1/4" x 15/16" strike accepts the bolt with precision alignment whether you install at the header (top) or threshold (bottom). The flat faceplate design keeps the door edge clean without protruding hardware that could snag clothing or catch during wheelchair or gurney movement. Available in two anodized finishes—628 clear aluminum (satin) or 313 dark bronze—the flushbolt blends with modern institutional aesthetics or disappears against darker frames. Mortise cylinders are sold separately, giving you flexibility to pair the 1870HM with any standard MS-cam cylinder from manufacturers you trust. Standard package includes the basic lock mechanism, actuator arm, stainless steel bolt guide, mounting screws, and installation instructions. For custom cylinder heights beyond the standard 13-1/2" (cylinder center to door end), Adams Rite offers special-order configurations up to full door height.

The 1870HM represents institutional-grade access control for paired door openings where key management and unauthorized-access prevention drive the spec. Explore our complete commercial locks catalog for coordinating deadlocks and hardware, or contact our specialists at 877-471-4870 to design a flushbolt configuration that matches your facility's security workflow.