1870 Series Cylinder-Operated Flushbolt

Designed for greater key control, the 1870 Cylinder-Operated Flushbolt prevents accidental locking of the inactive leaf of narrow stile aluminum paired doors. May be installed to lock at threshold or at header.


Designed for use instead of conventional flip-lever operated flushbolts, 1870 Cylinder-Operated Flushbolts give building management key control of the inactive leaf of paired narrow stile aluminum doors. Prevents casual locking of the inactive leaf by unauthorized persons. Uses same basic over-center action mechanism as MS® pivoted bolt deadlocks. Recommended for installation at both top and bottom of inactive door with MS1850S MS Deadlock in active doorfor greatest security. May be installed to lock at threshold or at header.


360° turn of key throws or retracts the hex-section bolt. Key can be removed only when bolt is in a positively locked or unlocked position. Lock accepts any standard1" [25.4 mm] length, 1-5/32" [29.4 mm] diameter mortise cylinder with MS® cam such as the 4036 Mortise Cylinder or thumbturn such as the 4066Thumbturn, available separately. Lock accepts cylinder from either or both sides.


Cylinder Backset: 31/32" [24.6 mm] or 1-1/8" [28.6 mm] only.

Cylinder Height: Standard length (cylinder center to retracted bolt tip) is 12" [304.8 mm] with ± 1-1/4" [31.8mm] adjustment. Please contact factory for other lengths available by special order.

Case: Steel with corrosion-resistant plating. Measures 1" x 6" x depth [25.4 mm x152.4 mm x depth]. Depth varies by backset.

Bolt: Stainless steel. Hexagonal 3/8" [9.5 mm] flat to flat, with 11/16" [17.5 mm] throw.

Strike: 1/2" [12.7 mm] diameter hole in metal thresholdor header is suitable. For wood thresholds, 4005 Strike is available separately.

Faceplate: Measures 1" x 6-7/8" [25.4 mm x 174.6 mm]. Available in choice of 313 Dark bronze anodized, 335 Black anodized, 628 Clear anodized.

Standard Package: Flushlock mechanism boxed with actuator arm attached, rod/bolt assembly unattached. Stainless steel bolt guide, mounting screws, and installation instructions included. Cylinder available separately.

Shipping Weight: 1-1/4 lbs [.57 kg].



Related Products: When purchasing this product, please consider the following related products, available separately:

Accessories Cylinders Special Order Options

4005 strike for wood threshold, 4104 Mounting Bridge, 91-0965 Mounting Kit for radiused door, 91-0966 Mounting Kit for beveled door, 26-00090XX Tube Spacer


Standard 1" length, 1-5/32” diameter mortise cylinder with MS® cam such as 4036 Mortise Cylinder, 4066 Thumbturn Other cylinder height / length available by special order. Please contact factory.