Deltana 18EFBZ 18" Extension Flush Bolt

An extension flush bolt is the top bolt that holds the inactive leaf of a pair of doors shut so the active leaf has something to latch into. The 18EFBZ gives you an 18 inch extension rod, which is what you use when the bolt has to reach a header that is higher than a standard flush bolt rod can cover, typically on tall or transom-height leaves. Mortised into the edge of the inactive door, throw the bolt up into a strike in the frame head and that leaf becomes fixed until you retract it.

Two, one top and one bottom, on the inactive leaf. The 18EFBZ covers the top position with an 18 inch extension reaching up to a strike in the frame head; the bottom leaf still needs its own bolt dropping into a floor strike. The 18EFBZ is sold each, so order per bolt position, not per pair of doors.

It mortises. An extension flush bolt sits flush in the edge of the door with only the faceplate showing, which is the point of it, no projecting hardware to catch on the active leaf or the frame. That means the inactive door needs to be prepped with a mortise pocket for the bolt body and the 18 inch extension rod, plus a face cutout for the plate. If you cannot cut the door, a surface mounted bolt is the alternative, not this one.

Round corners. That matters when you are matching an existing mortise, a radius corner plate will not sit right in a pocket routed square without cleanup, and it will leave gaps at the corners of a square cut. If the existing bolt in the door has square corners, plan on either recutting the pocket corners round or matching a square corner bolt instead.

Rod length is chosen off the reach you need, not preference. The 18EFBZ carries an 18 inch extension, so it is the one for tall leaves or where the bolt has to be positioned low enough to be operated by hand while still throwing into a strike well above it. On a standard height door where the bolt sits close to the head, a shorter extension is the correct part and an 18 inch rod is simply more than the door has room for.

Zinc, both the material and the substrate, with the finish applied over it. Zinc casts to tight detail and takes plated finishes well, which is why the same bolt is offered in polished brass and oil rubbed bronze without changing the body. It is a good match for interior door pairs; for exterior openings with weather exposure a solid brass or stainless bolt is the more usual specification.

Four: oil rubbed bronze, brushed nickel, polished brass and antique brass. All four are the same 18 inch zinc bolt, so pick on what the rest of the door hardware in the opening looks like. Oil rubbed bronze and antique brass will read darker and warmer against wood doors; brushed nickel matches satin chrome and stainless trim; polished brass matches bright brass lever sets and hinges.