BEST 9K Series Cylindrical Lever Lock, Grade 1, Less Core

The 9K fits BEST's standard door preparation for a cylindrical lock, ANSI A115.2 for 1-3/4 in doors: a 2-1/8 in cross bore and a 1 in edge bore at 2-3/4 in backset. It also needs two 5/16 in through-bolt holes at 12 and 6 o'clock, which BEST's KD303 jig drills from the existing bore.

The lock comes set for a 1-3/4 in door and is adjusted on site for doors up to 2-1/4 in, by turning the outside rose liner to the matching groove on the through-bolt studs. A 1-3/8 in door takes BEST's thin-door spacers; tell us the thickness before you order.

Every part here comes with the S3 strike, 4-7/8 x 1-1/4 in with a curved lip, for the standard ANSI frame cutout. BEST also makes the 9K with its STK strike, 2-3/4 x 1-1/8 in with a curved lip and box; if the frame is cut for that, tell us before you order.

BEST's instructions ask you to check that a hollow metal door is reinforced enough to hold the lock, and to consult the door's maker if it is not.

Keyed 9K locks ship less core. The 7-pin housing takes any BEST interchangeable core; a 6-pin core needs BEST's six pin spacer (part 1882120) or a 6-pin throw member, ordered separately, so tell us the pin count. The intruder takes two cores, inside and outside. We confirm the keyway, keying and number of keys in writing before a keyed core ships.

BEST makes 9K levers that take other makers' cylinders and cores, so a building can keep its existing keys: non-interchangeable cylinders from Corbin Russwin, Medeco, Sargent and Yale, and removable cores from Corbin Russwin, Sargent and Yale, among others (BEST 9K FAQ and adaptations sheet BA-0345). The cylinder or core is not included with these options, they are different part numbers from the ones on this page, and BEST says an interchangeable core lock cannot be changed to a non-interchangeable one or back. Tell us the make of your keys and we confirm the part in writing.

Each function locks and unlocks in its own way; How the part number is built gives BEST's description of each. In every function on this page the inside lever is always free. We do not advise which function a door needs; where codes apply, your AHJ makes the final call.

BEST lists the 9K with Underwriters Laboratories for 3-hour A label doors: single doors up to 4 x 10 ft and pairs up to 8 ft wide and 10 ft high. Whether a lock may go on your door is decided by your Authority Having Jurisdiction (AHJ).

You do not choose a hand when ordering: BEST's 9K order code has no handing position. The latch goes in with its bevel toward the strike, and each lever is pushed on pointing toward the hinges.

Send a photo of both sides of the door, the lock edge and the frame. We confirm the function, lever, rose, backset, strike and finish in writing before anything ships.

Fold BEST's template over the high edge of the door bevel and mark the drill points. BEST suggests 40-5/16 in from the floor to the lock's centerline; on a steel frame the latch centerline must line up with the center of the strike preparation.

Bore a 2-1/8 in hole from both sides to the center of the door, drill a 1 in hole from the edge into it and mortise the edge for the latch face. Fit the latch with its bevel toward the strike; its tabs should project into the 2-1/8 in hole.

Fit BEST's KD303 jig in the bore, engaged with the latch tabs and parallel with the door edge, and drill the two 5/16 in holes halfway into the door; turn the jig over and repeat from the other side.

Pull the rose locking pin and turn the outside rose liner in or out until the groove for the door's thickness, 1-3/4, 2 or 2-1/4 in, lines up with the hub face, and check that the pin locks into the rose liner.

Fit the chassis from the outside, so that the latch tabs engage the chassis frame and the latch tailpiece engages the retractor. Then the inside liner and through-bolts, the rose pressed onto the liner, and the lever, pushed on pointing toward the hinges until it seats.

Mortise the jamb for the strike box and plate in line with the latchbolt; BEST warns that the deadlocking plunger must not enter the strike opening, and that a gap of more than 1/8 in may reduce security. To fit the core, put the throw member on its back, turn the control key 15 degrees right, push the core into the lever, turn the key back and withdraw it. BEST warns that the control key removes cores and opens doors, so keep it secure.