Name: Marks USA G3 145K Single Cylinder Deadbolt Grade 1 Defender Cylindrical Cartridge Deadlatch, Less Cylinder
Brand: Marks USA
SKU: 145K 32D G3
Price: 116.56 USD
Availability: InStock

Product Overview
FAQs

Marks USA 145K Single Cylinder Deadbolt Grade 1 Defender Cylindrical Cartridge Deadlatch, Less Cylinder

The Marks USA 145K is a Grade 1 single cylinder deadbolt featuring the Defender Series cylindrical cartridge deadlatch, engineered for commercial-grade security and versatile cylinder compatibility. Designed for 1-3/4" door thickness (with spacer rings K1442/32D available for 1-3/8" doors), this unitized assembly installs into a standard 2-1/8" bore and accepts most manufacturers' conventional cylinders as well as high-security options from Medeco, Kaba, Multilock, and ASSA. The deadlatch carries an ANSI 156.5 Grade 1 rating with a UL 3-hour fire rating, while the deadbolt meets ANSI 156.5 Grade 1 standards, making this a dependable choice for demanding commercial applications.

Key Features

ANSI 156.5 Grade 1 Deadlatch: UL fire rated for 3 hours, providing certified protection for commercial fire-rated door assemblies.
ANSI 156.5 Grade 1 Deadbolt: Meets the highest ANSI grade standard for commercial deadbolts, ensuring robust security performance.
Latch Specifications: Grade 1 latch with 9/16" throw and 2-3/4" backset; latch front measures 1-1/8" x 2-1/4" for precise door preparation.
Unitized Assembly for 2-1/8" Bore: Series 1 cylindrical cartridge design installs easily into a standard 2-1/8" bore for straightforward retrofits and new installations.
Broad Cylinder Compatibility: Accepts Medeco, Kaba, Multilock, ASSA, and other high-security cylinders, as well as most manufacturers' conventional cylinders and IC core models for "Best" size cores.
Tapered Cylinder Collars: Engineered to prevent break-in attempts by wrenching, adding a critical layer of physical attack resistance.
Steel Shutter System: Eliminates access to mounting screws when the door is locked, protecting against tampering and unauthorized disassembly.
Door Thickness Flexibility: Standard fit for 1-3/4" doors; compatible with 1-3/8" doors using spacer rings K1442/32D.
Multiple Functions Available: Available in K (Cylinder x Turnpiece), L (Communicating Single Cylinder), M (Double Cylinder), KL (Cylinder x Lever), X (Turnpiece x Blank Plate), and KK (Cylinder x Knob) configurations.
Finish Options: Available in Bright Brass (3), Stainless Steel (32D), Dark Bronze (10B), and Satin Chrome (26D) to suit a variety of architectural requirements.

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
Product Function: Cylinder x Thumbturn
Latch Type Specification: Deadlocking
Keyway Profile: Less Core
Product Category: Mechanical Locks
Department: Door Hardware

Typical Applications

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

Why Marks USA 145K?

Marks USA 145K deadbolts and deadlatches are built to meet the rigorous demands of commercial door security, combining ANSI 156.5 Grade 1 certification with a UL 3-hour fire rating on the deadlatch for verified performance in life-safety applications. The Defender Series cylindrical cartridge design incorporates tapered cylinder collars and a steel shutter system to resist physical attack, while broad cylinder compatibility ensures seamless integration with virtually any keying system in use today.

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:: Less Core
Product Material:: Stainless Steel
Product Category:: Mechanical Locks
Backset (Distance):: 2-3/4"
Department:: Door Hardware

Marks USA 145K 32D G3 – Frequently Asked Questions

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

Standard fit is 1-3/4 inch doors. For 1-3/8 inch doors you add spacer rings K1442/32D, which have to be ordered along with the lock, so specify them up front if you are working on older interior openings. Anything thicker than 1-3/4 is outside what the 145K covers.

2) Does the Marks USA 145K deadbolt drop into an existing 2-1/8 inch bore with a 2-3/4 inch backset?

It does. The 145K is a unitized cylindrical cartridge assembly built for a standard 2-1/8 inch bore on a 2-3/4 inch backset, so on a door already prepped to that standard commercial pattern there is no new boring. The edge prep is the one to check: the latch front measures 1 x 2-1/4 inches. If the door is bored on a 2-3/8 inch backset, this is the wrong part.

3) The Marks USA 145K is listed less cylinder. What do I have to order with it?

The 145K ships without a cylinder or core, so the keying is a separate line. It takes most manufacturers' conventional cylinders, IC core models for Best size cores, and high-security cylinders from Medeco, Kaba, Multilock, and ASSA. That is the point of buying it less core: you key it into whatever system your building already runs instead of adding a second key. Locksmiths standardizing a site can hold the same cylinder across these and the rest of their openings.

4) Can I use a Marks USA 145K on a fire rated door?

The deadlatch portion carries a UL 3 hour fire rating, and both the deadlatch and the deadbolt are rated ANSI 156.5 Grade 1. That combination is what a hospital or school facility group needs on record for a rated opening. Note the rating applies to the deadlatch; the deadbolt is stated as Grade 1 without a separate fire figure.

5) Is a 9/16 inch throw enough, or do I need a 1 inch deadbolt throw?

The 145K's Grade 1 latch throws 9/16 inch. If your spec or your existing strike pocket is written around a 1 inch bolt projection, that is a different part: the Hager 3215 is a single cylinder commercial deadbolt with a 1 inch throw, Grade 2, fitting 1-3/8 to 1-3/4 inch doors. Where the drawing only calls for Grade 1 and a fire rated latch, the 145K meets it as is.

6) Which Marks 145 function do I order, cylinder and thumbturn or double cylinder?

The 145K is the K function: key cylinder outside, turnpiece inside. The same 145 body is built in L (communicating single cylinder), M (double cylinder), KL (cylinder x lever), X (turnpiece x blank plate), and KK (cylinder x knob). Pick K for a normal exit where someone inside needs to get out by hand. M, keyed both sides, is the one that traps occupants without a key, so check your egress requirements for the room before specifying it.

7) We key everything with small format interchangeable cores. What are the options besides the Marks USA 145K less cylinder?

The Marks USA 145K ships less core and accepts most manufacturers' conventional cylinders, IC core models for Best size cores, and high security cylinders from Medeco, Kaba, Multilock, and ASSA. Two peers are prepped the same way: the Arrow E61 26D IC is a Grade 2 single cylinder deadlock with SFIC prep, supplied less core, for doors 1-3/8 inch to 1-3/4 inch, and the Deltana CL200LAIC is a Grade 2 single deadbolt with interchangeable core, non cylinder, on a 2-3/4 inch backset. The Delaney LM Series 301702 is a Grade 1 single cylinder less core deadbolt in dull chrome US26D.

8) Which deadbolt should I use for a fire rated opening besides the Marks USA 145K?

The Cal-Royal CRB800 is the direct alternative for that opening: a Grade 1 heavy duty single cylinder deadbolt in the CRB800 Series with a UL 3-hour fire rated latch, cylinder x thumbturn function. The Marks USA 145K deadlatch is likewise UL fire rated for 3 hours and ANSI 156.5 Grade 1. Hager also carries fire rated cylinder x thumbturn deadbolts, including the Grade 1 3118 with a Schlage C keyway and 6-pin cylinder, which fits doors 1-3/8 inch to 1-3/4 inch.

9) What deadbolt do I use if the opening needs a key on both sides rather than a thumbturn?

The Marks USA 145K is a cylinder x thumbturn single cylinder deadbolt, so a double cylinder unit is the swap. The Design Hardware D1 Series is a Grade 1 double cylinder deadbolt rated extra heavy duty for 1-3/4 inch doors, the same thickness the 145K is built around. The Dexter DB1000-DCT is a Grade 1 double cylinder deadbolt for 1-3/8 inch to 1-7/8 inch doors, and the Hager 3214 is a Grade 2 double cylinder deadbolt with a Schlage C keyway covering 1-3/8 inch to 1-3/4 inch.

10) Which Grade 1 deadbolt fits a door thicker than 1-3/4 inch?

The Marks USA 145K is a standard fit for 1-3/4 inch doors, with spacer rings K1442/32D for 1-3/8 inch doors. For thicker stock, the Corbin Russwin DL3011 is a Grade 1 cylindrical deadlock, cylinder x blank, in the DL3000 Series, listed for 1-3/4 inch to 2-1/4 inch doors. Note the function difference: DL3011 is cylinder x blank rather than cylinder x thumbturn, so there is no inside turn. The Dexter DB1000-SCT is a Grade 1 cylinder x thumbturn deadbolt covering 1-3/8 inch to 1-7/8 inch.

11) What replaces a Marks USA 145K on a narrow stile aluminum or all glass door?

A cylindrical unit needs a 2-1/8 inch bore in the door face, which a narrow stile does not give. The Emtek 2050 and 2051 are European mortise deadbolts with an integrated roller latch in cylinder x thumbturn, square and round respectively, made for a mortise pocket in the stile. The Dormakaba D900 is a small case mortise dead bolt with a D cylinder, keyed different with SC keyways, in the D900 Series. The Marks USA 145K stays the choice where a standard 2-1/8 inch bore exists on a 1-3/4 inch door.

12) How does the Marks 145K resist someone attacking the lock from outside?

Two things do that work. The cylinder collars are tapered so a wrench cannot get a bite on them, and a steel shutter covers the mounting screws whenever the door is locked, so the lock cannot be unbolted from the outside face. Pair that with a high-security cylinder such as Medeco or ASSA and the weak point stops being the hardware.

13) What is the difference between the Marks 145K and a Grade 2 deadbolt like the Arrow DBX61?

Grade level and duty. The 145K is ANSI 156.5 Grade 1 on both the deadbolt and the deadlatch with a UL 3 hour rated latch, which is what high-traffic commercial and rated openings call for. The Arrow DBX61 is a Grade 2 single cylinder deadbolt, cylinder x thumbturn, from the DBX Series. Grade 2 is the step down in cycle and strength testing, fine for lower-traffic tenant doors but not the equivalent where a drawing specifies Grade 1.

14) What else could I buy if I need a Grade 1 deadbolt that fits a range of door thicknesses instead of just 1-3/4 inch?

The 145K is set up for 1-3/4 inch doors, with spacer rings for 1-3/8. If you are ordering across a mixed fleet of door thicknesses and do not want to track spacers, the Dexter DB1000 single cylinder deadbolt is Grade 1 and covers 1-3/8 to 1-7/8 inches, and the Accentra D111 is Grade 1 cylinder x thumbturn covering 1-3/8 to 1-3/4 inches on a 2-3/8 inch backset. The Accentra's backset is the catch if your doors are already bored at 2-3/4.

15) Will the Marks 145K deadlatch hold the door latched on its own, or do I still need a separate latchset?

The latch on the 145K is deadlocking, meaning the latchbolt locks against being shimmed or carded once the door closes. It is a deadbolt assembly with a cartridge deadlatch, not a lockset with a handle, so on a door that needs a lever or knob to operate it you still order the latchset or exit device separately. If you want the key cylinder and lever in one Marks 145 body, that is the KL function instead.

16) Can I standardize the Marks 145K across office, school, and multi-tenant doors in one building?

That is the case it is built for. Grade 1 on both bolt and latch, a single 2-1/8 inch bore and 2-3/4 inch backset prep across every opening, and less-core supply so one keying system covers the site. Marks lists it for commercial offices, schools, healthcare, retail, warehouse, multi-tenant residential, and government buildings. Where a door is 1-3/8 inch thick, the K1442/32D spacer rings bring it into the same standard rather than forcing a second model.

17) Is there a Grade 2 version of a single cylinder commercial deadbolt instead of the Grade 1 Marks USA 145K?

Several. The Arrow DBX61 is a Grade 2 single cylinder deadbolt, cylinder x thumbturn, in the DBX Series. The Dexter DB2000-SCT is a Grade 2 single cylinder cylinder x thumbturn deadbolt covering 1-3/8 inch to 1-3/4 inch doors. The Deltana CL200LA is a Grade 2 single deadbolt with the same 2-3/4 inch backset the Marks USA 145K uses, and the Falcon D211 is a Grade 2 cylinder x thumbturn deadbolt in the D200 Series rated medium duty. The 145K itself is ANSI 156.5 Grade 1 on both the deadbolt and the deadlatch, with the deadlatch UL fire rated for 3 hours.

18) Can a Codelocks CL200 surface deadbolt replace a Marks USA 145K?

They are not interchangeable. The Marks USA 145K is a keyed unitized cylindrical cartridge assembly that installs into a standard 2-1/8 inch bore on a 2-3/4 inch backset, ANSI 156.5 Grade 1, with the deadlatch UL fire rated for 3 hours. The Codelocks CL200 is a surface deadbolt with key override, rated light duty, so it mounts to the face of the door rather than filling an existing bore. The CL2200 is the electronic surface deadbolt in that family, rated medium duty, and the CL2210 is an electronic mortise deadbolt, which needs a mortise pocket, not a bore.

19) Which deadbolt has an ADA friendly thumbturn if the Marks USA 145K turnpiece is hard for tenants to operate?

The Cal-Royal LSD is the option built around that: a Grade 3 single cylinder deadbolt with an ADA ergonomic thumbturn, in the Chelsie LSD Series, cylinder x thumbturn, for doors 1-3/8 inch to 1-3/4 inch. The Marks USA 145K is a Grade 1 cylinder x thumbturn unit with a deadlatch UL fire rated for 3 hours, so the trade is between the grade and fire rating on one side and the easier turn on the other. Cal-Royal also offers the CB160, a Grade 2 single cylinder deadbolt with a tamper-resistant cylinder guard, which sits between the two on grade.

20) Which Grade 1 deadbolt gives me an inside key rather than a turn for a glass entry?

The Corbin Russwin DL3211 is a Grade 1 cylindrical deadlock in cylinder x blank, from the DL3200 Series, for 1-3/4 inch doors, so the inside face carries a blank plate instead of a turnpiece. The DL2211 is the Grade 1 cylindrical deadlock in the DL2200 Series, also cylinder x blank on 1-3/4 inch doors, in classroom function. The Marks USA 145K covers the turnpiece side of that decision as a cylinder x thumbturn unit; a turnpiece x blank plate configuration is also part of the Marks 145 function range.

21) Is there an electronic deadbolt alternative to a keyed Marks USA 145K for a multifamily property?

Yes, though the operation changes entirely. The Dormakaba Nova-D is an RFID multihousing smart electronic deadbolt in the Nova Series, and the Saffire LX-D is an RFID electronic deadbolt with BLE and electronic lock override. The Delaney KP400 is a Grade 2 electronic deadbolt with a programmable remote. The Marks USA 145K is a mechanical Grade 1 unit supplied less core that accepts conventional cylinders and high security cores from Medeco, Kaba, Multilock, and ASSA, which keeps it inside an existing master key system.

22) Will a Baldwin Estates or Emtek deadbolt work where a Marks USA 145K is specified?

They are built for a different kind of opening. The Baldwin Estates 8011 is a contemporary 1-5/8 inch double cylinder deadbolt in the Estate Series, and the Emtek #11 Tuscany is a lost wax cast bronze deadbolt in cylinder x thumbturn. Both are decorative residential trim rather than commercial cylindrical assemblies. The Marks USA 145K is a commercial ANSI 156.5 Grade 1 unit in stainless steel with a UL 3-hour fire rated deadlatch, a steel shutter system that blocks the mounting screws when locked, and tapered cylinder collars to resist wrenching. On a fire rated or high traffic commercial opening those are the features being specified.

23) What deadbolt do I use where access control needs to release the bolt electrically instead of a Marks USA 145K?

The DynaLock 1300 Series is a mortise electric deadbolt rated heavy duty, which lets the bolt be controlled from the access control system rather than by key and turn. The Detex DX Series is a hinge side locking dead bolt with multi-point security for openings that need the bolt engaging away from the strike edge. The Marks USA 145K is a mechanical Grade 1 cylinder x thumbturn deadbolt with a deadlocking latch, keyed and supplied less core, so it operates entirely at the door.

24) We are standardizing a facility on one deadbolt in stainless steel. What are the Grade 1 candidates?

The Marks USA 145K is a stainless steel Grade 1 unit, offered here in US32D stainless steel, ANSI 156.5 Grade 1 on both the deadbolt and the deadlatch with a UL 3-hour fire rating on the deadlatch. Among Grade 1 peers, the Delaney LM Series 301702 is a single cylinder less core deadbolt in dull chrome US26D, the Design Hardware D1 Series is a double cylinder Grade 1 rated extra heavy duty for 1-3/4 inch doors, and the Deltana CL200LM is a Grade 1 single cylinder deadbolt in cylinder x thumbturn. Mixing single and double cylinder within one standard is the call to make before ordering.

25) What finish does the Marks 145K come in for a commercial opening?

Stainless steel, US32D, is the orderable finish on the 145K, and the lock body itself is stainless steel. Marks builds the 145 family in Bright Brass (3), Dark Bronze (10B), and Satin Chrome (26D) as well, so if your building standard is a bronze or chrome opening, that is a finish request rather than a different lock. US32D is the usual pick when matching existing commercial hardware.

How fast can I get the Marks USA 145K 32D G3 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 145K 32D G3 come with a warranty?

Absolutely. The Marks USA 145K 32D G3 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 145K 32D G3?

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 Marks USA 145K 32D G3 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.

Marks USA G3 145K Single Cylinder Deadbolt Grade 1 Defender Cylindrical Cartridge Deadlatch, Less Cylinder

Write a Review

Marks USA