Sargent 78-40 Exposed Plug/Bar...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$159.00
$148.84
Sargent 78-40 Exposed Plug/Barrel Cylinder with 1-5/32" Solid Brass Construction

Sargent 78-40 Exposed Plug/Barrel Cylinder with 1-5/32" Solid Brass Construction

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Model: SGT-78-40
From the Conventional Key System Collection
$159.00
$148.84
Selected Finish is

In Stock (leaves warehouse same day if ordered before 3pm ET)

$159.00
$148.84
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Sargent 78-40 Series Mortise Lock Cylinder with 1-5/32" Solid Brass Construction

Professional Mortise Lock Cylinder Solution

The Sargent 78-40 Series Exposed Plug/Barrel Cylinder delivers professional-grade security for mortise lock applications with solid brass construction and 1-5/32" (29mm) diameter design. Engineered specifically for use with Sargent mortise locks featuring Escutcheon Trim (KE 3/4, LE 3/4), this cylinder system provides reliable keying solutions with standard 6-pin configuration and multiple finish options including 4, 15, and BSP.

Professional Features & Benefits

  • Precision Dimensions: 1-5/32" (29mm) diameter design ensures proper fit with compatible Sargent mortise lock systems.
  • Solid Brass Construction: Heavy-duty solid brass cylinder provides exceptional durability and corrosion resistance for long-term commercial applications.
  • Multiple Pin Configurations: Standard 6-pin operation with optional 7-pin specification available for enhanced security requirements.
  • Versatile Finish Options: Available in finishes 4, 15, and BSP to match existing hardware and architectural requirements.
  • Complete Keying Package: All cylinders supplied 1-bitted with 2 nickel silver keys unless otherwise specified for immediate installation.
  • Mortise Lock Compatibility: Designed specifically for Sargent mortise locks with Escutcheon Trim (KE 3/4, LE 3/4) for seamless integration.
  • Series Function Options: Available in 78-41 (6 pin single cylinder), 78-42 (6 or 7 pin single cylinder), and 78-43 (6 or 7 pin all functions except 50) configurations.

Technical Specifications

  • Refer to manufacturer documentation for complete technical specifications.

Installation & Operation

This cylinder component is designed for use with compatible Sargent mortise locks with Escutcheon Trim. Refer to the parent device installation instructions and manufacturer documentation for proper integration. Ensure compatibility with existing hardware before installation.

Professional Applications

  • Commercial Office Buildings
  • Educational Facilities
  • Healthcare Institutions
  • Government and Municipal Buildings
  • Multi-Tenant Residential Properties
  • Industrial and Warehouse Facilities
  • Retail Establishments

Why Choose Sargent Quality?

Sargent 78-40 Series cylinders deliver professional-grade reliability with solid brass construction and precision 6-pin keying systems. Engineered specifically for demanding commercial mortise lock applications, these cylinders provide the dependable security performance that professionals trust for critical access control installations.

Product Specs

Series:
40 Series
Product Type:
Cylinders
Product Group:
Mechanical Locks
Product Subgroup:
Parts and Accessories
Subcategory:
Parts and Accessories
Commercial/Residential:
Commercial
Collection:
Conventional Key System
Parts and Accessories Type:
Replacement Parts
Product Attribute:
Parts and Accessories
Product Category:
Mechanical Locks
Department:
Door Hardware

Sargent SGT-78-40 – Frequently Asked Questions

1) What is the difference between the Sargent 78-41, 78-42 and 78-43 mortise cylinders?
Those three designations are the function variants of the 78-40 exposed plug/barrel cylinder. The 78-41 is a 6-pin single cylinder. The 78-42 is a single cylinder available in 6 or 7 pin. The 78-43 covers 6 or 7 pin for all functions except function 50. Pick the one that matches the mortise lock function you are keying, then set pin count, cam and keyway on the order.
2) Will the Sargent 78-40 cylinder fit my Sargent mortise lock?
It is built for Sargent mortise locks using Escutcheon Trim (KE 3/4, LE 3/4), at a 1-5/32 inch (29mm) diameter. If your mortise lock uses that escutcheon trim arrangement, this is the cylinder size Sargent specifies for it. Lever or knob trim on a different Sargent trim family can call for a different cylinder length, so match the trim designation on the lock before ordering.
3) Which cam do I need to order with a Sargent 78-40 cylinder?
Cam choice is a required selection: Standard, 101, 105, 106, 112, 113 or 115. The cam is what drives the lock body, so it has to match the specific Sargent mortise lock or device the cylinder is going into. If you are replacing an existing Sargent cylinder, pull it and match the cam on the back rather than guessing.
4) Do Sargent 78-40 cylinders come keyed, and can I get them keyed alike across a building?
Unless you specify otherwise, cylinders ship 1-bitted with two nickel silver keys. For real keying, choose KD (keyed different) when every door needs its own key, or KA (keyed alike) when a group of doors should share one key, which is what property managers usually want for a floor or a mechanical suite. Standard keying is the third option.
5) Should I order 6 pin or 7 pin?
Six pin is the standard configuration and is what most Sargent conventional systems are built around. Seven pin is the option when the master key system needs the extra chamber for more levels or higher security, and it is available on the 78-42 and 78-43 but not the 78-41. Match whatever your existing system uses, because a 7-pin cylinder will not operate on a 6-pin key system.
6) What finishes does the Sargent 78-40 cylinder come in to match my existing door hardware?
Fourteen finishes are available: 03 bright brass, 04 satin brass, 09 bright bronze, 10 satin bronze, 10B oil rubbed dark oxidized satin bronze, 10BE, 10BL, 14 bright nickel, 15 satin nickel, 20D dark statuary bronze, 32 bright stainless, 32D satin stainless, BSP black suede powder coat and WSP white suede powder coat. Since the plug and barrel are exposed through the escutcheon, pick the finish that matches the trim, not just the door.
7) Is the 78-40 an interchangeable core cylinder?
No. The 78-40 is a conventional key system cylinder with an exposed plug and barrel, so the pin stack is in the cylinder body and re-keying means pinning it or swapping the cylinder. If you want to change keys on a door without a locksmith at the door, you need a small format or large format interchangeable core cylinder and matching housing instead.
8) What do I need to know before ordering a Sargent 78-40 cylinder?
Four things get specified: function size (78-41, 78-42 or 78-43), pin count (6 or 7), cam (Standard, 101, 105, 106, 112, 113 or 115), and keying (standard, KD or KA), plus keyway and finish. The cam and the keyway are the two that most often get an order sent back, because the cam has to suit the lock body and the keyway has to suit the existing key system.
9) Is the Sargent 78-40 a solid brass cylinder, and is it suitable for high-traffic commercial doors?
Solid brass construction, and it is a commercial-rated part rather than a residential one. Brass resists corrosion, which matters on exterior openings and in humid plant or healthcare environments. It is sold as a replacement part, so it is the cylinder you buy to re-key or refinish an existing Sargent mortise lock without replacing the lock body.
How fast can I get the Sargent SGT-78-40 delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Sargent SGT-78-40 come with a warranty?
Absolutely. The Sargent SGT-78-40 is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Sargent SGT-78-40?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
Why buy the Sargent SGT-78-40 from ZenSupply?
ZenSupply makes it easy to get the commercial door hardware you need—fast shipping, expert support, and rewards on every order. Our team is always ready to help you choose the right product for your project.
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