We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Polished brass mortise entry lockset with wide face plate and screw-on knobs

Marks USA

Marks USA 91A/3-X Polished Brass Right Hand Mortise Entry Door Lock

SKU CH-XMZN-8VC3H MPN 91A/3-X

Polished brass mortise entry lockset with 2-1/2" backset, surface-mounted wide face plate, screw-on knobs and solid brass cylinder

  • FinishPolished Brass
  • Selling UnitBox
  • TypeMortise Entry Surface Mounted Lockset with 1-1/4" x 8" Wide
  • FeaturesSurface Mounted plate assemblies - Screw On Knobs with Swive
  • MaterialBrass
  • Backset2-1/2"
  • Polished brass finish resists corrosion and matches traditional hardware
  • 1-1/4" x 8" wide face plate covers large door cut-outs cleanly
  • Solid brass cylinder with two keys provides reliable keyed entry
  • Right-hand mortise configuration fits standard entrance door preparations
  • Screw-on knobs with swivel spindle allow secure, smooth operation

Product Overview

The Marks USA 91A/3-X is a polished brass mortise entry lockset designed for right-hand doors. It features a surface-mounted configuration with a wide face plate measuring 1-1/4" x 8" and a 2-1/2" backset. The set includes screw-on knobs with a swivel spindle and a solid brass cylinder supplied with two keys. This hardware provides a traditional entrance function for commercial or residential openings.

Suitable Applications

This lockset suits installers fitting a right-hand mortise entrance where a wide face plate and surface-mounted brass trim are specified. The screw-on knob design allows straightforward attachment during installation. It is not suitable for left-hand door swings or for projects requiring a narrow face plate, an integrated rose design, or electronic access control. Buyers needing a different backset dimension should verify compatibility before ordering.

Critical Specification

The 2-1/2" backset is the single measurement that determines whether this lock aligns with the existing door preparation. An incorrect backset prevents the latch and deadbolt from engaging the strike plate correctly, making the hardware unusable for that opening. Confirm this dimension matches the door bore before purchase to ensure proper fit and function.

Highlights

  • Polished brass finish resists corrosion and matches traditional hardware
  • 1-1/4" x 8" wide face plate covers large door cut-outs cleanly
  • Solid brass cylinder with two keys provides reliable keyed entry
  • Right-hand mortise configuration fits standard entrance door preparations
  • Screw-on knobs with swivel spindle allow secure, smooth operation

Specifications

BrandMarks
Model91A/3-X
FinishPolished Brass
Selling UnitBox
TypeMortise Entry Surface Mounted Lockset with 1-1/4" x 8" Wide Face Plate
FeaturesSurface Mounted plate assemblies - Screw On Knobs with Swivel Spindle
MaterialBrass
Backset2-1/2"
KeyingKeyed Different
StyleKnobs
SeriesMetro
FunctionEntrance

Questions about this item

Which handing should I order for a door that swings inward on the right?

Choose the right-hand mortise lockset — it is built for doors hinged on the right when viewed from the outside.

What does the 2-1/2" backset mean once the lock is installed?

It places the centre of the knob and cylinder 2-1/2 inches from the door edge, so the bore must match that distance.

How does the surface-mounted face plate affect the door preparation?

The 1-1/4" x 8" brass plate fastens to the door face with screws, avoiding a deep mortise pocket.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.