Falcon X521 Heavy Duty Grade 1...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,104.00
$872.22
Falcon Falcon X521- Office Lock - Heavy Duty Single Cylinder Cylindrical Lock, Grade 1 FAL-X521

Falcon X521 Heavy Duty Grade 1 Office Cylindrical Lock with Single Cylinder

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Model: X521LD EG 626
$1,104.00
$872.22
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$1,104.00
$872.22
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Falcon X521 Heavy Duty Grade 1 Office Cylindrical Lock with Single Cylinder

Professional Heavy-Duty Cylindrical Lock Solution

The Falcon X521 delivers Grade 1 commercial-grade security with heavy-duty cylindrical knob lock construction designed for demanding office applications. This UL listed lock accommodates door thickness ranges from 1-3/8" to 2-1/4" with a standard 2-3/4" backset and features interchangeable cores for convenient re-keying. ANSI/BHMA A156.2 Series 4000 Grade 1 certified for maximum durability and UL 3-hour A label fire rated for life safety compliance.

Professional Features & Benefits

  • Door Compatibility: Accommodates door thickness from 1-3/8" to 2-1/4" with 2-3/4" backset for versatile installation options.
  • Grade 1 Durability: ANSI/BHMA A156.2 Series 4000 Grade 1 certification ensures maximum performance in high-traffic commercial applications.
  • Interchangeable Core System: Quick and convenient re-keying with cores compatible with SFIC products from other manufacturers for flexible key management.
  • Heavy-Duty Construction: Brass or cold-formed steel construction with zinc dichromate coating provides superior rust resistance and long-term reliability.
  • Fire Safety Compliance: UL 3-hour A label fire rating meets critical life safety requirements for commercial buildings.
  • Reinforced Rose Design: Heavy-wrought brass, bronze or stainless steel roses over steel through-bolted rose inserts provide exceptional strength and security.
  • XC Construction Option: Optional stainless steel and nonferrous chassis with stainless steel trim resists corrosion in marine and high-moisture environments.
  • Manufacturer Warranty: 10-year limited warranty provides long-term protection and confidence in product reliability.

Technical Specifications

  • ANSI/BHMA: F81
  • Backset (Distance): 2-3/4",Strike,5185 - Square Corner
  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Door Hand Direction: Non-Handed
  • Door Thickness Range: 1-3/8" to 2-1/4"
  • Duty Level: Heavy Duty
  • Fire Rating: Yes
  • Grade: Grade 1
  • Keyed: Yes
  • Keyed Function: Single Cylinder
  • Lock Function: Office
  • Lock Type: Cylindrical
  • Product Attribute: Cylindrical Locks
  • Product Category: Mechanical Locks
  • Product Function: Office
  • Product Group: Mechanical Locks
  • Product Subgroup: Bored Locksets
  • Product Type: Knobsets
  • Series: X Series
  • Standard Strike: 1-1/4" x 4-7/8", ANSI, Square curved lip corner, no box
  • Subcategory: Cylindrical Locks
  • UL Listing Type: UL Listed (3 Hour A Label)

Installation & Operation

  1. Review manufacturer specifications and verify door preparation requirements including door thickness between 1-3/8" and 2-1/4", 2-3/4" backset, and handing as applicable to this product.
  2. Use manufacturer-provided templates to mark mounting hole locations accurately on door and frame surfaces.
  3. Prepare door and frame by drilling required holes and routing as specified in manufacturer instructions.
  4. Install all mounting hardware and secure the device to door and frame per manufacturer torque specifications.
  5. Adjust operational components for proper alignment, latching, and smooth operation throughout the full range of motion.
  6. Test device operation to verify proper function and make final adjustments as needed. Refer to manufacturer documentation for complete installation details and troubleshooting.

Professional Applications

  • Commercial Office Buildings
  • Educational Facilities
  • Healthcare Institutions
  • Government and Military Facilities
  • Marine Environment Applications
  • Multi-Tenant Residential Properties
  • Industrial and Warehouse Facilities

Why Choose Falcon Quality?

Falcon X521 cylindrical locks deliver professional-grade reliability with heavy-duty brass or cold-formed steel construction and zinc dichromate coating for superior corrosion resistance. ANSI/BHMA Grade 1 certification and UL 3-hour fire rating ensure compliance with the most demanding commercial building requirements. Backed by a 10-year limited warranty and engineered for applications where dependable security and long-term performance are essential.

Manufacturer Resources

Falcon Locks Catalog

Product Specs

Product Group:
Mechanical Locks
Series:
X Series
Grade:
Grade 1
Duty Level:
Heavy Duty
Standard Strike:
1-1/4" x 4-7/8", ANSI, Square curved lip corner, no box
Subcategory:
Cylindrical Locks
ANSI/BHMA:
F81
Product Subgroup:
Bored Locksets
Keyed Function:
Single Cylinder
Commercial/Residential:
Commercial
Keyed:
Yes
Product Type:
Knobsets
Lock Type:
Cylindrical
UL Listing Type:
UL Listed (3 Hour A Label)
Lock Function:
Office
Product Attribute:
Cylindrical Locks
Backset (Distance):
2-3/4",Strike,5185 - Square Corner
Product Function:
Office
Door Hand Direction:
Non-Handed
Door Thickness Range:
1-3/8" to 2-1/4"
Fire Rating:
Yes
Product Category:
Mechanical Locks
Department:
Door Hardware

Falcon X521LD EG 626 – Frequently Asked Questions

1) What does the office function on the Falcon X521 actually do at the door?
The X521 is an F81 office function lock. The outside knob is locked or unlocked by the key, and turning the inside knob always retracts the latch for free egress. It takes a single cylinder on the outside only, so there is no key access from the inside. That is the standard setup for a private office or a conference room where staff want to lock up on the way out but never want the door to trap anyone inside.
2) Will the Falcon X521 fit a 2 inch thick door?
Yes. The X521 covers door thicknesses from 1-3/8 inches up to 2-1/4 inches, so a 2 inch door is inside the range with no special kit. That range is wider than most cylindrical knob locks, which typically stop at 1-3/4 inches, and it is why the X521 gets specified on thick institutional doors and on older openings that do not measure out to a standard 1-3/4.
3) Can I put a Falcon X521 knob lock on a fire rated office door?
Yes. The X521 is UL Listed with a 3 hour A label rating, so it can go on fire door assemblies up to that rating. Fire doors also need the latch to stay positively latched, and the office function keeps a latchbolt engaged at all times, unlike a passage or dummy set.
4) Can I order the Falcon X521 to take my building's existing interchangeable cores?
Yes. Order it less SFIC and drop in the small format interchangeable cores you already key in house, which lets you pull the X521 into an existing masterkey system without a locksmith visit. Other cylinder choices are a conventional 6-pin cylinder or less cylinder if you are supplying your own. Falcon's cores also work with SFIC product from other manufacturers.
5) Which keyway should I pick on the Falcon X521 if my building is keyed to Schlage C?
Schlage C is one of the keyway choices, so the X521 can be cut to the same keys as a Schlage C keyed building. The other options are Falcon G standard, E, H, K, L, N and P, or None if you are ordering less cylinder and supplying your own.
6) What is the closest Grade 1 keyed office equivalent to the Falcon X521 from another manufacturer?
The Corbin Russwin CK4851 is the nearest match: it is a Grade 1 entrance/office cylindrical knob lock with a conventional cylinder, covering doors 1-3/8 inch to 2 inch. The Falcon X521 is a Grade 1 heavy duty office cylindrical knob lock with a single cylinder and covers 1-3/8 inch to 2-1/4 inch doors, so the Falcon spans a slightly thicker door. Both are keyed knob functions rather than lever trim.
7) Does the Falcon X521 have to be ordered left or right hand?
No handing needed. The X521 is non-handed, so one part number works on a left or right hand door and you can stock a single lock across a building. The latch face is the only thing to watch, and that is a separate selection.
8) Is a knob lock like the Falcon X521 a bad choice where ADA lever hardware is required?
Knobs require grasping and twisting, so on openings where your code official is enforcing lever operation you want a lever, not a knob. The X521 is a knobset. If you need Grade 1 heavy duty keyed hardware on the same kind of opening and a knob will not pass, look at a Grade 1 lever from the same class of product rather than forcing the knob.
9) What are the alternatives to the Falcon X521 if I need Grade 1 heavy duty but a different function?
For storeroom function, where the outside knob stays locked at all times and the key retracts the latch, the Sargent 8XG04 is a Grade 1 heavy duty single cylinder knob lock on a 2-3/4 inch backset. For an entrance function Grade 1 knob, the BEST 8K Series entrance lock is single cylinder heavy duty. If the door only needs to latch with no key at all, the Schlage D10S is a Grade 1 heavy duty passage knob.
10) Is a Grade 1 lock like the Falcon X521 overkill for a small office suite, or should I go Grade 2 or 3?
Grade 1 is the top commercial tier and it is what you want on high traffic openings, main office doors and anything institutional. For interior doors in a light traffic suite, Grade 2 or 3 keyed office locks cost less and still latch: the Corbin Russwin CK4851 is an entrance/office cylindrical knob lock on a conventional cylinder, and the Cal-Royal BER00 is a Grade 3 entrance/office knob with a Kwikset keyway. What you give up going down is cycle life and, in the case of the X521, the 2-1/4 inch door capacity and the UL 3 hour A label.
11) Will the Falcon X521 hold up in a coastal or high humidity building?
For marine and high moisture openings, specify the XC construction option, which uses a stainless steel and nonferrous chassis with stainless steel trim. The standard build is brass or cold-formed steel with a zinc dichromate coating. Pairing XC with the 630 satin stainless steel finish gives you the most corrosion resistant combination offered.
12) Does the Falcon X521 come as a complete set, or do I need to buy the latch and strike separately?
Latch, strike, keyway and keying are all required selections made with the lock, so the X521 ships as a complete working set once those are chosen. What you decide on the order form is the latch face style, the strike to match your frame prep, the keyway, and whether you want a conventional 6-pin cylinder, less cylinder, or less SFIC for your own cores.
13) What finishes does the Falcon X521 come in for matching existing office hardware?
Six finishes are offered: 605 bright brass, 606 satin brass, 613 satin bronze oil-rubbed, 625 bright chrome, 626 satin chrome and 630 satin stainless steel. For most commercial buildings 626 satin chrome is the standard match, and 630 is the usual pick alongside stainless push plates and closers.
14) Is a Schlage A170 dummy trim a substitute for the Falcon X521?
No. The Schlage A170 is a Grade 2 single dummy trim, a non-keyed knob with no latch and no locking at all. The Falcon X521 is a keyed Grade 1 office lock with a single cylinder and a 2-3/4 inch backset latch. Dummy trim is only for inactive leaves or closet doors that do not latch.
15) What is a lower cost keyed office knob alternative if Grade 1 is not required?
The Pamex FTF Baron knob lockset in entrance/office function is a Grade 3 keyed knob for doors 1-3/8 inch to 1-3/4 inch, and the Cal-Royal BER00 is a Grade 3 entrance/office knob lock with a Kwikset keyway for the same door range. The Falcon X521 is the Grade 1 heavy duty option with a 1-3/8 inch to 2-1/4 inch door range and interchangeable core capability.
How fast can I get the Falcon X521LD EG 626 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 Falcon X521LD EG 626 come with a warranty?
Absolutely. The Falcon X521LD EG 626 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 Falcon X521LD EG 626?
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 Falcon X521LD EG 626 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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