Rockwood 557 Lever Extension Flush Bolt

The 557 throws 3/4 inch on a 3/4 inch backset, and the supplied strike measures 15/16 x 2-1/4 inches. If the bolt hole in your head frame and threshold is already cut for a 3/4 inch backset bolt, the 557 drops in. If your old bolt sat further off the door edge, the mortise has to move, so plan on a new prep rather than reusing the hole.

Manual. The 557 is a lever operated extension flush bolt, so someone throws and retracts each bolt by hand at the door edge. If you need the inactive leaf to release on its own when the active door swings, that is an automatic flush bolt, and the Ives FB41 automatic flush bolt set for wood doors is that type with a 90 minute fire rating. For a keyed release instead, Adams Rite 1877 is a cylinder operated flushbolt for paired wood doors.

Fasteners come in the box: 7 each #8 x 3/4 inch flat head combo screws, 4 each #8-32 x 1/2 inch flat head machine screws, and 4 each #8 countersunk washers. The one thing worth adding is the Rockwood 570 dust proof strike for the floor, which keeps grit out of the bottom strike so the bolt still drops all the way. On any opening where the bottom bolt sits in a traffic path, order it with the bolt.

The Rockwood 557 is lever operated, so someone has to throw and retract the bolt by hand at the inactive leaf. If the opening calls for the inactive leaf to latch on its own, the Ives FB41 is an automatic flush bolt set for wood doors with a 3/4 inch throw and a 90 minute fire rating, and the Ives FB42 is a top automatic flush bolt for wood doors with an auxiliary fire latch. The ABH 1860P/1862P is an automatic flush bolt pair, fire rated 3 hour, with a thermal lock. Automatic bolts retract when the active leaf opens; the 557 stays where it is set until a person moves it.

Two groups get mistaken for it. The Adams Rite MS1880/MS1881 and MS2180 are two-point flushbolts, the MS1880 with an interlock mechanism and the MS2180 an auto-release type with a Smartlock mechanism; those throw top and bottom from one mechanism rather than being a single lever operated extension bolt like the 557. The other group is metal door hardware: the ABH 1858 is a universal bottom fire bolt with manual operation, and the ABH 1854 set is for metal doors, while the 557 is specified for plastic and wood covered doors. The International Door Closers FB-1202 also differs in the prep it needs, with a 5/8 inch throw and 7/8 inch backset against the 557's 3/4 inch throw and 3/4 inch backset.

The face plate is 1 x 6-3/4 inches, so that is the cutout in the door edge at the top and bottom of the inactive leaf. The lever extension body runs behind it up the edge. Door strength is maintained by a corner reinforcing plate, which is what makes this bolt acceptable on a fire rated wood or plastic covered leaf where cutting into the corner would otherwise be a problem.

It's a commercial grade bolt, certified to ANSI A156.16 with the L04261 function designation. For a facility standardizing flush bolts across wood door pairs, that A156.16 listing is the line item a spec writer looks for, and it is the same certification that supports its use on the 1-1/2 hour fire rated leaves it is approved for.

Reach. The 557 lever extension runs the bolt operator down from the mortised face plate so you can throw it without climbing to the top of the leaf, and it carries the corner reinforcing plate that keeps a wood or plastic covered fire door intact where it is cut. A short corner mount bolt like the Trimco 3999SE 6 inch square end or the Orca 6 inch flush bolt with radius corners is a simpler part, mortised at the corner and operated right where it sits, which is fine on a standard height leaf but means reaching the head of a 10 foot door.

No, the 557 is thrown and retracted by hand at the door edge with no key control. For keyed operation on a pair, the Adams Rite 1870 series is a cylinder operated flushbolt with key control, and the 1877 is the cylinder operated version for paired wood doors. Adams Rite MS1880 and MS1881 are two point flushbolts with an interlock mechanism if you want both bolts driven together.

The Rockwood 557 is operated by a lever at the bolt, so anyone reaching the inactive leaf can throw or retract it. Where the inactive leaf has to be under key control, the Adams Rite 1870 is a cylinder-operated flushbolt with key control, and the Adams Rite 1877 is a cylinder-operated flushbolt for paired wood doors. Those require a cylinder and a keying decision; the 557 does not.

The Rockwood 557 is an extension flush bolt in cast brass with a corner reinforcing plate that maintains door strength, built for fire rated plastic and wood covered doors. On a non-rated interior pair where the extension body is not needed, the Delaney 4108 is a 6 inch square end solid brass flush bolt, the Orca 86SQ is a 6 inch flush bolt with radius corners, and the Trimco 3999 is a 6 inch corner mount flushbolt with a rounded end, with the 3999SE the square end version of the same body. Those are short-body bolts mortised into the door edge rather than extension bolts.

The Rockwood 557 throws 3/4 inch with a 3/4 inch backset and meets ANSI A156.16, L04261. Peers carrying the same 3/4 inch throw are the ABH 1855S single manual flush bolt for metal doors, the Ives FB358 manual flush bolt with a 1/2 inch bolt diameter, and the Ives FB41 automatic flush bolt set for wood doors. The International Door Closers FB-1202 throws 5/8 inch with a 7/8 inch backset, so the strike pocket depth and edge prep are different.

Three: 605 bright brass, 613 satin bronze oil rubbed, and 626 satin chrome. The bolt is cast brass underneath. On a building where the other openings are already 626, matching is straightforward; 613 is the one to pick against dark bronze levers and pulls.

No handing to specify. The 557 mortises into the edge of the inactive leaf and the lever throws the bolt into the head frame or the floor strike, so the same part works on a left or right hand pair. What you do need to settle is door construction (wood or plastic covered, not metal), leaf size within 4 feet by 10 feet, and finish.

It's built for that traffic. Cast brass body, commercial rated, and Rockwood hardware of this type is used across institutional buildings, offices, retail, educational, detention, sports facilities, and hospitality. On a floor bolt that sees mopping and grit, add the Rockwood 570 dust proof strike so the bottom bolt keeps seating fully.

The Rockwood 557 is thrown by a lever at the bolt. The Delaney 4101 is a 7 inch slide type mortise in flush bolt, operated by sliding the bolt rather than by a lever, and the Delaney 4363 is a 7 inch mortise extension flush bolt. Both are the same broad length class as the 557's 1 inch by 6-3/4 inch face plate, but the operation at the door edge is different, so decide whether the crew is expecting a lever to grip or a slide to push.