Emtek LC4-PRIDB Thumbturn Privacy Latch

Both. The LC4-PRIDB is an adjustable-backset latch that sets to either 2-3/8 or 2-3/4 inches, and it is ordered by backset as well, so you pick the setting you need at the order form. Those are the two standard residential bore backsets, so if the existing hole in your door was drilled for a passage or privacy knob, one of the two settings will land on it.

Doors from 1-3/8 to 1-3/4 inches thick, with a 2-1/8 inch cross bore. That is the standard prep on residential interior doors, so a bedroom or bath door already drilled for a knob or lever takes this latch without new boring. Doors thicker than 1-3/4 inches are out of range.

For Emtek privacy knobsets and leversets, yes. The LC4-PRIDB is sold as a replacement latch, not a complete lockset, so it swaps the latch body while your existing knob, lever and rose stay on the door. Since it adjusts between the two common backsets and covers 1-3/8 to 1-3/4 inch doors, one part number handles a mixed set of interior openings; you only need to keep the finish and the faceplate corner style consistent with what is on each door.

No. The LC4-PRIDB is a residential privacy latch. For a rated opening you need a latch carrying the listing, such as the Kwikset 83521 RCAL plain latch or the Kwikset 84290 square corner plainlatch with a 2-3/8 inch backset, both UL rated.

The Deltana DLP23875 is the nearest peer. It is a drive-in latch with an adjustable 2-3/8 inch or 2-3/4 inch backset and a Passage/Privacy function, which matches the LC4-PRIDB on both backset adjustment and the privacy/bed/bath function it serves. The difference is at the door edge: the Deltana is a drive-in latch that seats into a bored edge without a mortised faceplate, while the Emtek latch uses a faceplate supplied in round corner or square corner form. If the existing prep already has a mortised faceplate pocket, that pocket is the deciding detail.

The Emtek LC4-PRIDB is built for doors 1-3/8 inch to 1-3/4 inch thick. For a thicker slab, the Deltana DLP23875 drive-in latch carries a door thickness range of 1-3/8 inch to 2 inch and holds the same Passage/Privacy function, so a 2 inch bedroom or bath door can be latched without changing the function of the opening. Confirm the edge prep first, since the DLP23875 is a drive-in latch rather than a faceplate latch.

The LC4-PRIDB covers both. The faceplate is round corner or square corner, so match whatever the mortise in your door edge already is. If the old latch face has rounded corners the door was routed with a radius bit; a square-corner plate in that pocket leaves gaps at the corners.

Ten finishes, each available in both backsets: Oil Rubbed Bronze (US10B), Polished Nickel Lifetime (US14), Satin Nickel (US15), Pewter (US15A), Flat Black (US19), Polished Chrome (US26), Polished Brass Lifetime (US3), Unlacquered Brass (US3NL), Satin Brass (US4), and French Antique (US7). Order the code that matches the knob or lever rose you are keeping, since the latch faceplate shows on the door edge.

Depends on how the edge of the door is prepped. The Emtek LC4-PRIDB uses a faceplate that mortises into the door edge and screws in, which is what you want when the existing door was routed for a plate. If the door edge has no mortise and just a plain 1-inch bore, a drive-in latch like the Deltana DLP23875 passage/privacy latch presses straight into the hole with no routing. Both adjust between 2-3/8 and 2-3/4 inch backsets.

They are not interchangeable by function. The Deltana DLE23875 is an Entry latch, while the Emtek LC4-PRIDB serves the Privacy/Bed/Bath function and works with a thumbturn on the inside face. If the opening is a bedroom or bathroom door that needs an inside thumbturn, the entry latch is the wrong function even though both are adjustable drive-in-era replacement latches in the same backset territory. The DLE23875 does carry a 1-3/8 inch to 2 inch door thickness range if the opening is in fact an entry door.

It looks close and is not a match. The Kwikset 84290 is a square corner plainlatch fixed at a 2-3/8 inch backset and is catalogued to the deadbolt strike plate function, so it does not carry the Privacy/Bed/Bath function the LC4-PRIDB serves, and it cannot be reset to 2-3/4 inch the way the Emtek latch adjusts. A square corner faceplate alone does not make two latches equivalent - the function and the backset adjustment have to agree as well.

The Kwikset 83518 is an RCAL adjustable square drive UL 3 hour latch and the 83521 is an RCAL plain latch, UL 3 hour, built for the Kwikset BBL, KNL, CNL and PLL lock bodies. Both are tied to that Kwikset chassis family and are catalogued to the deadbolt strike plate function. The Emtek LC4-PRIDB is a brass thumbturn privacy latch on a tubular lock type serving the Privacy/Bed/Bath function. A buyer replacing the latch inside a Kwikset knob or lever should stay with the RCAL part that matches the chassis; a buyer replacing the latch behind an Emtek privacy thumbturn should stay with the LC4-PRIDB.

Steel latch body with brass in the latch assembly. It is a mechanical, non-electronic part, so there is no wiring or power to plan for on the opening.

The Deltana DLP23875 is the more basic route. It is a drive-in Passage/Privacy latch with the same 2-3/8 inch or 2-3/4 inch adjustable backset, so it covers either bore spacing without the mortised faceplate step the Emtek latch's round or square corner faceplate requires. The Emtek LC4-PRIDB is a non-keyed brass latch matched to Emtek thumbturn privacy trim and finished across ten options from Flat Black to Unlacquered Brass, which matters when the latch face is visible on the door edge next to matching hardware.