The Schlage THP-8219-CH-F is the UL 3-hour fire rated privacy latch assembly for the Schlage LT Series Grade 2 tubular levered lock, designed for 1-3/8" thin doors with a 2-3/8" backset. The faceplate measures 1" x 2-1/4" square corner. Mounting screws are included. The critical distinction in this part number is the F suffix, which identifies this as the fire-rated latch. The non-fire-rated equivalent is THP-8219-CH. Both share identical physical dimensions and backset, but only the THP-8219-CH-F carries UL 3-hour fire listing for installation on rated door assemblies.

This is a field replacement latch for an existing LT Series privacy lock installation on a fire-rated opening. It is not a complete lock replacement. If the installed door is on a rated corridor, stairwell, or fire separation wall and the latch assembly needs service, this is the correct replacement. Substituting the non-rated THP-8219-CH on a fire-rated opening would void the door assembly's UL listing.

Why the Fire Rating on the Latch Assembly Matters for Schlage Tubular Locks

On a fire-rated door assembly, every component must carry an appropriate listing. The door, the frame, the hardware, and the latch assembly are all evaluated as part of the complete assembly by UL or another recognized testing laboratory. The Schlage LT Series is available with an optional fire rating on its latches specifically to meet this requirement- the LT Series lock body itself does not carry the fire rating, but the latch assembly does when the F variant is specified.

The UL 3-hour rating on the THP-8219-CH-F means the latch has been tested under positive pressure fire conditions (UL10C) in addition to neutral pressure (UL10B) to ensure it holds the door in the latched position during a fire event. A latch that fails under heat or pressure allows a fire door to swing open, defeating the rated assembly entirely. The spring-loaded bolt and latch body construction on the F version is designed to maintain function at elevated temperatures for the rated duration.

Schlage LT Series: What the Privacy Latch Does

The LT40 and LT40F are the Schlage LT Series privacy functions. The inside push-button on the rose locks the outside lever, preventing entry from outside while leaving the inside lever always free for immediate egress. Turning the inside lever releases the push-button lock automatically, so occupants cannot lock themselves in from inside without a deliberate secondary action to re-engage the button.

The THP-8219-CH-F latch works with this privacy function by providing the 2-3/8" backset configuration for 1-3/8" thin doors. This shorter backset is the less common LT specification- the standard door thickness LT installation uses the THP-8319-F-CH at 2-3/4" backset with a 1-1/8" wide faceplate. Before ordering, confirm the door thickness: 1-3/8" doors get the THP-8219 series, doors thicker than 1-3/4" get the THP-8319 series. Ordering the wrong backset will result in a latch that doesn't seat correctly against the strike.

Schlage Door Latch Assembly: LT Series Latch Part Number System

The Schlage LT Series latch catalog organizes by backset, function, and fire rating using a consistent part numbering format. The THP prefix applies to all LT Series latches. The 83xx numbers designate 2-3/4" backset. The 82xx numbers designate 2-3/8" backset. The first digit after the 8 identifies function: 01 is passage, 19 is privacy. The F suffix adds UL 3-hour fire rating. The CH suffix identifies the chrome-finish housing.

So THP-8219-CH-F decodes to: THP series, 2-3/8" backset (82), privacy function (19), chrome housing (CH), fire rated (F). All seven LT Series finish options use the same latch body and F designation- the finish code at the end of the ordering string changes the faceplate appearance only, not the fire rating or dimensions.

SecurityParts stocks OEM Schlage LT Series latch assemblies across all backset, function, and fire-rating configurations.