Name: Marks USA MAR145M 145M Double Cylinder Deadbolt with Grade 1 Defender Cylindrical Cartridge Deadlatch
Brand: Marks USA
SKU: 145M/32D
Price: 95.15 USD
Availability: InStock

Product Overview
FAQs

Marks USA 145M Double Cylinder Deadbolt with Grade 1 Defender Cylindrical Cartridge Deadlatch

The Marks USA 145M is a commercial-grade double cylinder deadbolt featuring a Grade 1 Defender cylindrical cartridge deadlatch engineered for demanding security applications. Designed for 1-3/4" door thickness (compatible with 1-3/8" doors using spacer rings K1442/32D), this unitized assembly installs into a standard 2-1/8" bore and delivers a 9/16" latch throw with a 2-3/4" backset. The cylinder x cylinder (M) function requires a key on both sides, providing enhanced access control for commercial environments. Marks USA's versatile 145 Series accepts most manufacturers' conventional cylinders as well as high-security cylinders from Medeco, Kaba, Multilock, and ASSA.

Key Features

ANSI Grade 1 Rated: Deadbolt meets ANSI 156.5 Grade 1 standards; deadlatch meets ANSI 156.5 Grade 1 and carries a UL fire rating of 3 hours for maximum code compliance.
Double Cylinder Function: Cylinder x cylinder (M) configuration requires key operation from both sides, providing superior security control for commercial doors.
Unitized Assembly for 2-1/8" Bore: Streamlined installation into a standard 2-1/8" bore opening for straightforward retrofits and new installations.
Door Thickness Compatibility: Designed for 1-3/4" doors; compatible with 1-3/8" doors using spacer rings K1442/32D for flexible application.
Latch Specifications: 9/16" throw with 2-3/4" backset and a 1-1/8" x 2-1/4" latch front for precise, secure engagement.
Tapered Cylinder Collars: Engineered tapered collars prevent break-in attempts by wrenching, adding a critical layer of physical security.
Steel Shutter System: Eliminates access to mounting screws when the door is locked, protecting against tampering and unauthorized disassembly.
Broad Cylinder Compatibility: Accepts Medeco, Kaba, Multilock, ASSA, and other high-security cylinders, as well as IC core models for "Best" size cores and most conventional cylinders.
Strike Included: Ships with strike #1136, 2-3/4" strike for complete out-of-box installation readiness.

Certifications & Compliance

ANSI 156.5 Grade 1 — Deadbolt
ANSI 156.5 Grade 1 — Deadlatch
UL Fire Rated — 3 Hours (Deadlatch)

Technical Specifications

Latch Front: 1" x 2-1/4"
Product Group: Mechanical Locks
Product Subgroup: Bored Locksets
Subcategory: Cylindrical Locks
Commercial/Residential: Commercial
Keyed: Yes
Function Description: Single Cylinder Deadbolt
Product Function: Cylinder x Thumbturn
Latch Type Specification: Deadlocking
Keyway Profile: Marks C
Product Category: Mechanical Locks
Department: Door Hardware

Typical Applications

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

Why Marks USA 145M?

Marks USA 145M deadbolts deliver professional-grade security through a combination of ANSI 156.5 Grade 1 certification, a 3-hour UL fire-rated deadlatch, tapered cylinder collars, and a steel shutter system that blocks access to mounting screws when locked. The Series 1 cylindrical cartridge design and broad cylinder compatibility — including Medeco, Kaba, Multilock, and ASSA high-security options — make the 145M a trusted choice for commercial door security where dependable, tamper-resistant performance is essential.

Manufacturer Resources

Marks USA Product Catalog

Product Specs

Latch Front:: 1” x 2-1/4”
Grade:: Grade 1
Product Group:: Mechanical Locks
Product Subgroup:: Bored Locksets
Product Type:: Deadbolts
Subcategory:: Cylindrical Locks
Commercial/Residential:: Commercial
Keyed:: Yes
Function Description:: Single Cylinder Deadbolt
Product Attribute:: Deadbolts
Product Function:: Cylinder x Thumbturn
Latch Type Specification:: Deadlocking
Keyway Profile:: Marks C
Product Material:: Stainless Steel
Product Category:: Mechanical Locks
Backset (Distance):: 2-3/4"
Department:: Door Hardware

Marks USA 145M/32D – Frequently Asked Questions

1) Will the Marks USA 145M deadbolt fit a 1-3/8 inch door, or is it 1-3/4 only?

The 145M is built for 1-3/4 inch doors, and it will go on a 1-3/8 inch door with spacer rings K1442/32D. Without those rings on a thinner door the cylinders sit proud and the assembly will not clamp up correctly. On standard commercial 1-3/4 inch openings no spacers are needed.

2) What bore and backset do I need to prep for a Marks 145M deadbolt?

A standard 2-1/8 inch cross bore takes the 145M as a unitized assembly, with a 2-3/4 inch backset on the standard build and a 2-3/8 inch backset offered as well. The latch front measures 1 x 2-1/4 inches. If the door is already bored 2-1/8 inch for a cylindrical lock, the deadbolt drops into that prep, so measure the existing backset from the door edge to the center of the bore and order to match.

3) Does a double cylinder deadbolt like the Marks 145M need a key on both sides, and where can I legally use one?

Yes, cylinder x cylinder means a key operates it from inside and outside, with no thumbturn. That is the point of the M function for storefronts and glass-adjacent doors where someone could reach the inside turn. It also means the door cannot be opened from inside without a key, so it is generally not permitted on a required means of egress door. For an egress opening, order a cylinder x thumbturn deadbolt instead.

4) Will the Marks 145M deadbolt latch into my existing strike?

The bolt throws 9/16 inch and the 145M ships with strike #1136, a 2-3/4 inch strike. A 9/16 inch throw is short for a deadbolt, so it needs a properly aligned strike with the right depth pocket. If your frame already has a deep 1 inch deadbolt pocket the shorter bolt will still engage, but if you are replacing a mortise deadbolt the existing strike cutout will not match the 1 x 2-1/4 inch face. Use the supplied strike.

5) Can I key the Marks 145M into my existing Medeco or Best system?

The 145 Series accepts most manufacturers' conventional cylinders plus high security cylinders from Medeco, Kaba, Multilock and ASSA, and there are IC core models that take Best size cores. Standard build uses the Marks C keyway. So if the building is already keyed on a restricted system, you can carry that system onto this deadbolt rather than running a second key. Specify the cylinder or the less-core IC version when you order.

6) Is the Marks 145M deadbolt approved for a fire rated door?

The deadlatch carries a UL fire rating of 3 hours, and both the deadbolt and the deadlatch meet ANSI 156.5 Grade 1. That is the rating a stair door or a rated corridor door needs on the hardware side. Note the double cylinder function still has to satisfy the egress requirements for that opening.

7) What is the closest Grade 1 double cylinder deadbolt to the Marks USA 145M?

The Design Hardware D1 Series double cylinder deadbolt is the nearest straight equivalent. It is Grade 1, double cylinder function, rated extra heavy duty, and built for 1-3/4 inch doors - the same door thickness the Marks USA 145M is designed around. The Dexter DB1000 double cylinder is also Grade 1 double cylinder and covers 1-3/8 to 1-7/8 inch doors, so it spans a wider thickness range in one part number. Where the 145M differs from both is keying flexibility: the 145 Series accepts most conventional cylinders plus Medeco, Kaba, Multilock and ASSA high-security cylinders, so an existing keying system carries over.

8) Is there a Grade 1 deadbolt with a UL 3-hour fire rated latch besides the Marks USA 145M?

The Cal-Royal CRB800 is a Grade 1 heavy duty single cylinder deadbolt with a UL 3-hour fire rated latch, which puts it on the same fire and grade footing as the Marks USA 145M whose deadlatch carries a 3-hour UL rating. The difference is function: the CRB800 is cylinder x thumbturn, keyed outside and turned by hand inside, while the 145M is keyed on both faces. On a fire-rated egress opening, confirm which side the code official will allow to be key-operated before choosing between the two.

9) What should be used instead of a double cylinder deadbolt on a door that has to allow free egress?

A key on the inside face is the wrong answer on an egress door. The Arrow E60 Grade 2 exit deadlock is non-keyed with a blank plate outside and a thumbturn inside, so the door always releases from the secure side by hand and fits 1-3/8 to 1-3/4 inch doors. Where the outside still needs to be keyed, the Accentra D111 is a Grade 1 cylinder x thumbturn deadbolt for 1-3/8 to 1-3/4 inch doors, and the Falcon D111 is a Grade 1 heavy duty cylinder x thumbturn with an adjustable backset. The Marks USA 145M cylinder x cylinder function is for openings where key control on both faces is intended.

10) Which double cylinder deadbolts look like a substitute for the Marks USA 145M but are not commercial equivalents?

Several parts carry a double cylinder function without being commercial Grade 1 hardware. The Callan Model 210S is a Grade 3 double cylinder deadbolt and the Deltana 7312KA2 is a Grade 3 double cylinder for 1-3/8 to 2 inch doors - both sit two grades below the Marks USA 145M, which is Grade 1. The Baldwin Reserve contemporary round and square double cylinder deadbolts and the Emtek 8323 Modern Disc double cylinder in brass are decorative residential trim rather than commercial deadbolts. And the Baldwin Reserve 8BR0618001 is a deadbolt spacer, a component for a double cylinder installation, not a lock.

11) What deadbolt fits a door thicker than 1-3/4 inches?

The Corbin Russwin DL3011 Grade 1 cylindrical deadlock covers 1-3/4 inch through 2-1/4 inch doors, which is the option for thick doors. The Deltana 7312KA2 double cylinder handles 1-3/8 to 2 inch. The Marks USA 145M is built for 1-3/4 inch doors and drops to 1-3/8 inch with spacer rings K1442/32D, so it covers the thin side rather than the thick side of that range. Note the DL3011 is cylinder x blank, keyed on one face with no operation from the other, so it is not a like-for-like swap for a two-key opening.

12) What finishes and backsets does the Marks 145M come in?

Three finishes on the cylinder trim: US3 bright brass, US10B dark bronze and US32D stainless steel, each available in both 2-3/4 inch and 2-3/8 inch backset. US32D is the usual match for commercial openings already running satin stainless levers and closers; US10B suits dark bronze storefront. The body material is stainless steel.

13) What makes a Grade 1 deadbolt like the Marks 145M worth it over a Grade 2 like the Arrow DBX61?

Grade 1 is the heaviest ANSI/BHMA duty level, intended for high traffic commercial openings; Grade 2 is the medium duty tier. The Marks 145M is Grade 1 with a 3 hour UL fire rated deadlatch, tapered cylinder collars that resist wrenching, and a steel shutter that blocks the mounting screws when the door is locked. The Arrow DBX61 is a Grade 2 single cylinder deadbolt, cylinder x thumbturn. For an apartment interior or a low traffic back office the Grade 2 is enough; for an exterior entry or a rated door, go Grade 1.

14) I need a Grade 1 double cylinder deadbolt but the 145M does not suit my door. What else is there?

Two direct Grade 1 double cylinder alternatives: the Design Hardware D1 Series, extra heavy duty and rated for 1-3/4 inch doors, and the Dexter DB1000 double cylinder, which covers a wider 1-3/8 to 1-7/8 inch thickness range and is the one to reach for on an odd thickness door. If Grade 2 is acceptable, the Hager 3214 double cylinder covers 1-3/8 to 1-3/4 inch and is fire rated.

15) Is the Marks 145M a mortise deadbolt or a bored one?

It is a bored, cylindrical deadbolt: a unitized assembly that goes into a 2-1/8 inch cross bore, not a mortise pocket. If the existing door has a routed mortise case in the edge, this is the wrong type and you want a mortise deadlock such as the Dormakaba D900 small case mortise deadbolt. Going the other way, a bored deadbolt is far quicker to install on a hollow metal or wood door with no existing prep.

16) Does a deadlatch deadbolt like the Marks 145M stop someone shimming the bolt with a card?

Yes. The latch type is deadlocking, meaning the bolt is positively held once thrown so it cannot be pushed or shimmed back. Combined with the tapered cylinder collars, which give a wrench nothing to bite on, and the steel shutter that covers the mounting screws when the door is locked, the exposed attack points on this deadbolt are limited.

17) I need to standardize deadbolts across a building. Can I mix single and double cylinder in the same Marks 145 Series?

Yes. The 145 Series carries the function as a suffix, with M being cylinder x cylinder. Interior and egress doors take the cylinder x thumbturn version of the same series, so the trim, the 2-1/8 inch bore prep, the 2-3/4 inch backset and the finish all stay consistent across the building while the function changes door to door. Keying stays common through the Marks C keyway or whichever high security cylinder you standardize on.

18) What Grade 1 deadbolt takes an interchangeable core instead of a conventional cylinder?

The Delaney LM Series is a Grade 1 single cylinder less core deadbolt in dull chrome US26D, shipped ready for a core to be dropped in. The Arrow E61 26D IC is a Grade 2 single cylinder deadlock with SFIC prep less core for 1-3/8 to 1-3/4 inch doors. The Marks USA 145 Series is also available in IC core models sized for Best cores, so a facility already standardized on small format cores can stay on the 145 platform rather than changing manufacturers.

19) Which deadbolt works when the door already has a lockset and only a keyed deadbolt is being added above it?

For adding a deadbolt over an existing lockset, the Corbin Russwin DL3211 and DL2211 are Grade 1 cylindrical deadlocks for 1-3/4 inch doors, keyed one side with a blank plate on the other. The Falcon H2101 takes the opposite approach, combining an entrance lockset and a Grade 2 single cylinder deadbolt in one interconnected unit, which changes both preps rather than adding to one. The Marks USA 145M is a standalone deadbolt keyed on both faces, so it works alongside whatever lockset is already in the lower bore.

20) Which deadbolt has a thumbturn easier to operate for accessibility?

The Cal-Royal LSD is a Grade 3 single cylinder deadbolt with an ADA ergonomic thumbturn for 1-3/8 to 1-3/4 inch doors, built for an easier grip on the inside face. The Marks USA 145M has no thumbturn at all - it is keyed on both faces - so on an opening where inside operation has to be tool-free and low-effort, the two are not interchangeable.

21) Do I have to buy a cylinder separately for the Marks 145M?

Standard 145M builds come keyed on the Marks C keyway with the strike #1136 included, so the box is complete for a straight install. Order the IC core version less core if you are pinning it into a Best format system, and specify the brand if you want Medeco, Kaba, Multilock or ASSA cylinders instead. Remember it is a double cylinder, so it takes two cylinders, not one.

22) Is there an electronic deadbolt alternative to a keyed double cylinder deadbolt?

For openings moving off mechanical keys, the Codelocks CL2200 is a medium duty electronic surface deadbolt and the CL2210 is an electronic mortise deadbolt. The Dormakaba Saffire LX-D is an RFID electronic deadbolt with BLE and electronic lock override, and the Nova-D is an RFID multihousing smart deadbolt. The Delaney KP400 is a Grade 2 electronic deadbolt with a programmable remote. These change the credential and the door prep; the Marks USA 145M goes into a standard 2-1/8 inch bore and stays on a mechanical key on both faces.

How fast can I get the Marks USA 145M/32D 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 Marks USA 145M/32D come with a warranty?

Absolutely. The Marks USA 145M/32D 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 Marks USA 145M/32D?

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

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Marks USA MAR145M 145M Double Cylinder Deadbolt with Grade 1 Defender Cylindrical Cartridge Deadlatch

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