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Polished brass mortise lockset with surface-mounted screw-on knobs, left-hand storeroom function

Marks USA

Marks USA 91DW/3 Polished Brass Left Hand Mortise Door Lock

SKU CH-0DAW-CMD73 MPN 91DW/3

Polished brass mortise lockset with storeroom function, left-hand operation and 2-1/2" backset

  • FinishPolished Brass
  • Selling UnitBox
  • TypeMortise Surface Mounted Lock Knob Vestibule Function Always
  • FeaturesSurface Mounted plate assemblies - Screw On Knobs with Swive
  • MaterialBrass
  • Backset2-1/2"
  • Polished brass finish resists corrosion and matches period hardware
  • Storeroom function keeps the outside locked at all times
  • Solid brass cylinder with two keys provides durable keying
  • Left-hand configuration fits doors hinged on the left
  • Surface-mounted screw-on knobs simplify installation on existing doors

Mortise Lock for Storeroom Doors

The Marks Metro 91DW/3 is a left-hand mortise lockset with a polished brass finish. It operates on a storeroom function so the outside knob is always locked and requires a key for entry. The latch-only design omits a deadbolt and rocker arm for simplified operation. Solid brass plates and a brass cylinder with two keys complete the hardware.

Surface-Mounted Installation Requirements

This lockset uses surface-mounted plate assemblies with screw-on knobs and a swivel spindle. A 2-1/2 inch backset is needed to align the mechanism with the door preparation. The face plate measures 1-1/16 by 7-5/8 inches and mounts directly to the door edge. No thumb turn is present on the interior side, so egress relies on the inside knob alone.

Commercial-Grade Brass Construction

Solid brass components resist wear in high-traffic commercial settings. The keyed-different cylinder provides individual access control for each lock. The latch-only configuration suits doors that do not require a deadbolt. Buyers needing a deadbolt, right-hand handing or a thumb-turn interior will need a different lockset.

Highlights

  • Polished brass finish resists corrosion and matches period hardware
  • Storeroom function keeps the outside locked at all times
  • Solid brass cylinder with two keys provides durable keying
  • Left-hand configuration fits doors hinged on the left
  • Surface-mounted screw-on knobs simplify installation on existing doors

Specifications

BrandMarks
Model91DW/3
FinishPolished Brass
Selling UnitBox
TypeMortise Surface Mounted Lock Knob Vestibule Function Always Locked Storeroom Latch Only Lockset
FeaturesSurface Mounted plate assemblies - Screw On Knobs with Swivel Spindle
MaterialBrass
Backset2-1/2"
KeyingKeyed Different
StyleKnobs
SeriesMetro
FunctionStoreroom

Questions about this item

How far back from the door edge does the 2-1/2" backset place the knob center?

The knob center sits two and a half inches from the door edge, matching standard mortise prep for commercial doors.

Does the solid brass cylinder and latch generate noticeable heat or noise during continuous daily operation?

Mechanical mortise hardware has no electrical components, so it produces no heat and only the quiet click of the latch engaging.

What door thickness and handing must the opening already have for this left-hand lock to install correctly?

The lock is built for left-hand doors; verify your door thickness matches the mortise pocket depth and that the hinge side is on the left when pushing the door open.

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