BEST 9K Intruder Function Grad...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$1,123.00
$695.65
BEST 9K Intruder (IN) Lock - Grade 1 Cylindrical Keyed Lever Lock

BEST 9K Intruder Function Grade 1 Cylindrical Lever Lock with Visual Lockdown Indicator

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Model: 9K37IN15CSTK626
$1,123.00
$695.65
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$1,123.00
$695.65
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BEST 9K Intruder Function Grade 1 Cylindrical Lever Lock with Visual Lockdown Indicator

Professional Classroom Security Solution with Emergency Lockdown Capability

The BEST 9K Intruder Function cylindrical lever lock provides critical classroom security with a visual lockdown indicator that shows which way to turn the key for secure emergency locking. This Grade 1 heavy-duty lock features a 2-3/4" backset, solid brass 9/16" latch throw, and cast construction lock hub designed for 1-3/4" to 2-1/4" doors. Tested to exceed 10 times the BHMA Grade 1 criteria by UL, this lock delivers proven reliability for educational facility security applications.

Professional Features & Benefits

  • Visual Lockdown Indicator: Easy-to-understand marking on classroom side shows which way to turn the key for emergency locking from inside the classroom.
  • Grade 1 Heavy-Duty Performance: Tested to exceed 10 times the BHMA Grade 1 criteria by UL for exceptional durability in high-traffic educational environments.
  • Cast Construction Lock Hub: Protects critical lock components from everyday use and abuse with hardened steel through-bolt studs for maximum lever torque resistance.
  • Pre-Assembled Chassis Design: Out-of-the-box installation with 2-1/16" diameter chassis to fit standard 2-1/8" door holes conforming to ANSI A115.2.
  • Solid Brass Latch: 9/16" throw latch with 2-1/4" x 1-1/8" beveled front provides secure latching performance.
  • Attack-Resistant Design: Rose locking pin assembly and slotted key release cam create maximum attack resistance while maintaining key access and lever functionality.
  • Interchangeable Core System: Allows for quick re-keying and customized master keying for facility-wide access control management.
  • 10 Year Limited Warranty: Comprehensive manufacturer warranty provides long-term protection and confidence in product reliability.

Technical Specifications

  • ANSI/BHMA: F11
  • Backset (Distance): 2-3/4"
  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Door Hand Direction: Non-Handed
  • Duty Level: Heavy Duty
  • Electronic: No
  • Function Description: Latch: Turning the key in the inside/outside lever, Rotating the inside or outside lever. Outside lever lock or unlocked by turning the key in the outside lever. Inside lever is locked or unlocked by turning the key in the inside lever
  • Grade: Grade 1
  • Handle Type: Lever
  • Keyed: Yes
  • Keyed Function: Double Cylinder
  • Lock Function: Intruder
  • Lock Type: Cylindrical
  • Product Attribute: Cylindrical Locks
  • Product Category: Mechanical Locks
  • Product Function: Intruder
  • Product Group: Mechanical Locks
  • Product Model: S
  • Product Subgroup: Bored Locksets
  • Product Substrate: Corrosion-Treated Steel
  • Product Type: Leversets
  • Series: 9K Series
  • Standard Latch: 9/16" Throw
  • Standard Strike: 2-3/4 x 1-1/8" with curved lip and box
  • Subcategory: Cylindrical Locks
  • Warranty: 10 Year Limited

Installation & Operation

  1. Review manufacturer specifications and verify door preparation requirements including door thickness (1-3/4" to 2-1/4"), backset distance (2-3/4" standard), and handing as applicable to this product.
  2. Use manufacturer-provided templates to mark mounting hole locations accurately including standard ANSI A115.2 preparation plus two additional 5/16" diameter through-bolt holes at 12 o'clock and 6 o'clock positions.
  3. Prepare door by drilling required holes including 2-1/8" chassis hole and through-bolt mounting holes as specified in manufacturer instructions.
  4. Install the pre-assembled chassis and secure with hardened steel through-bolt studs per manufacturer torque specifications for maximum lever torque resistance.
  5. Adjust lever operation and visual lockdown indicator alignment for proper emergency locking function and smooth operation throughout the full range of motion.
  6. Test device operation including key function from both sides, lever operation, and visual indicator clarity. Refer to manufacturer documentation for complete installation details and troubleshooting.

Professional Applications

  • Educational Facility Classroom Security
  • School Administrative Offices
  • Healthcare Institution Patient Areas
  • Commercial Office Buildings
  • Government and Municipal Buildings
  • Multi-Tenant Residential Properties
  • Emergency Lockdown Applications

Why Choose BEST Quality?

BEST 9K Series cylindrical locks deliver professional-grade reliability with cast construction components and corrosion-treated steel rated to exceed 10 times BHMA Grade 1 criteria. The 10 Year Limited warranty provides comprehensive protection for demanding commercial and educational applications. Engineered for critical security applications where dependable emergency lockdown performance and visual operation indicators are essential for protecting occupants and staff.

Manufacturer Resources

9K Series Catalog

Product Specs

Series:
9K Series
Grade:
Grade 1
Duty Level:
Heavy Duty
Handle Type:
Lever
Keyed Function:
Double Cylinder
Warranty:
10 Year Limited
Standard Latch:
9/16" Throw
Standard Strike:
2-3/4 x 1-1/8" with curved lip and box
ANSI/BHMA:
F11
Product Group:
Mechanical Locks
Product Subgroup:
Bored Locksets
Product Type:
Leversets
Subcategory:
Cylindrical Locks
Keyed:
Yes
Electronic:
No
Commercial/Residential:
Commercial
Function Description:
Latch: Turning the key in the inside/outside lever, Rotating the inside or outside lever. Outside lever lock or unlocked by turning the key in the outside lever. Inside lever is locked or unlocked by turning the key in the inside lever
Lock Type:
Cylindrical
Lock Function:
Intruder
Product Attribute:
Cylindrical Locks
Product Model:
S
Product Function:
Intruder
Door Hand Direction:
Non-Handed
Product Substrate:
Corrosion-Treated Steel
Product Category:
Mechanical Locks
Backset (Distance):
2-3/4"
Department:
Door Hardware

BEST 9K37IN15CSTK626 – Frequently Asked Questions

1) How does the BEST 9K Intruder function lock work for a classroom lockdown?
The 9K Intruder (IN) function lets a teacher lock the outside lever from inside the room without stepping into the corridor. Turning the key in the inside lever locks or unlocks the inside lever; turning the key in the outside lever locks or unlocks the outside lever. Either lever retracts the latch when unlocked, and turning the key in either lever also retracts it. A marking on the classroom side shows which way to turn the key, so nobody has to remember under pressure.
2) What door thickness and bore does the BEST 9K cylindrical lever lock need?
It is built for 1-3/4 inch to 2-1/4 inch doors. The chassis is 2-1/16 inches in diameter and drops into the standard 2-1/8 inch cross bore per ANSI A115.2, but the 9K also needs two extra 5/16 inch through-bolt holes at the 12 and 6 o'clock positions for the hardened steel through-bolt studs. If your existing prep is plain 161 with no through-bolt holes, plan on drilling those two.
3) Will the BEST 9K latch into the strike already in my frame?
The standard latch throws 9/16 inch with a 2-1/4 x 1-1/8 inch beveled front, and the lock ships with a matching strike. You can order it with either a 2-3/4 inch ANSI strike or a 4-7/8 inch ANSI strike, so match the choice to what is cut into your frame: hollow metal frames are usually prepped for the 4-7/8 inch ANSI strike, wood frames more often for the shorter one. The standard strike is 2-3/4 x 1-1/8 inches with a curved lip and box.
4) What backsets does the BEST 9K Intruder lever lock come in for wide stile or unusual doors?
Standard is a 2-3/4 inch backset, and 3-3/4 inch and 5 inch backsets are also available for doors with wider stiles or where the lever needs to sit further off the edge. Pick the backset before anything else, because it has to match the cross bore centerline already in the door.
5) What grade and ANSI function is the BEST 9K Intruder lock, and is it enough for a school corridor?
Grade 1, heavy duty, ANSI/BHMA function F11, and BEST states it is tested by UL to exceed 10 times the BHMA Grade 1 criteria. The chassis uses a cast lock hub and corrosion-treated steel with hardened steel through-bolt studs to resist lever torque, which is the failure mode you see most in high traffic student corridors.
6) Can the BEST 9K be master keyed into an existing BEST small format interchangeable core system?
Yes, the 9K uses BEST's interchangeable core system, so cores pull with a control key for fast rekeying and can be brought into a facility-wide master key plan. It is a double cylinder keyed lock, meaning there is a core on both the corridor side and the classroom side, so a lockdown keyset has to be issued for the inside cylinder as well.
7) What is the closest alternative to the BEST 9K intruder lock for a classroom door that needs lockdown from inside?
The Dexter C1000 classroom security lock (DEX-C1000-CSEC) is the nearest functional peer. It is a Grade 1 cylindrical lever lock in classroom security function, keyed with a clutching lever, for doors 1-3/8 inch to 1-3/4 inch thick. The BEST 9K intruder is also Grade 1 cylindrical, non-handed, with a 2-3/4 inch standard backset and a visual lockdown indicator on the classroom side showing which way to turn the key. Doors thicker than 1-3/4 inch are where the two part ways, since the 9K covers 1-3/4 inch through 2-1/4 inch.
8) Is a standard classroom function lever the same thing as the BEST 9K intruder function?
No. A standard classroom lock such as the Dexter C1000 classroom (DEX-C1000-CLRM) or the Cal-Royal AG03 classroom lever is keyed from the outside only, so a teacher has to step into the corridor to secure the door. The BEST 9K intruder function is a double-cylinder arrangement: the outside lever is locked or unlocked by key from outside, and the inside lever is locked or unlocked by key from inside, with a visual indicator marking the lockdown direction. If the requirement is locking from within the room, the classroom function is not a substitute.
9) Do I have to specify handing when ordering a BEST 9K lever lock?
No. The 9K cylindrical lever is non-handed, so one part number covers left and right hand openings. That matters if you are standardizing a school or a portfolio of buildings, since you stock one lock instead of two.
10) What lever styles, roses and finishes can I get on the BEST 9K so it matches the other doors in my building?
Three lever styles (contour with angle return, curved with return, curved without return) and two rose sizes, a 3 inch convex C rose and a 3-1/2 inch convex D rose. Finishes run 605 bright brass, 606 satin brass, 611 bright bronze, 612 satin bronze, 613 oil-rubbed satin bronze, 618 bright nickel, 619 satin nickel, 622 matte black, 625 bright chrome, 626 satin chrome, 626AM satin chrome antimicrobial, and 690 statuary dark bronze. The 626AM option is worth a look in healthcare and school settings where touch surfaces are a concern.
11) Is there a difference between the BEST 9K Intruder lock and a classroom security lock like the Dexter C1000?
Both address the same problem, locking the corridor lever from inside the room. The BEST 9K Intruder is Grade 1 with a visual indicator showing which way to turn the key and separate key control of the inside and outside levers. The Dexter C1000 classroom security lever is also Grade 1 and is listed for 1-3/8 to 1-3/4 inch doors, so it is the one to look at if your doors are thinner than the 9K's 1-3/4 to 2-1/4 inch range. Dexter also offers a straight classroom function C1000 if you only need the outside lever keyed from the corridor.
12) I only need a keyed storeroom or entry lever, not a lockdown function. What else is there?
If nobody needs to lock the door from inside the room, an intruder function is more lock than the opening calls for. The Cal-Royal AG05 is a Grade 2 storeroom lever with a deadlocking latchbolt, and the Hager 2580 is a Grade 2 storeroom lever with the Withnell design for 1-3/8 to 2 inch doors. For classroom function keyed from the corridor only, the Cal-Royal AG03 is a Grade 2 classroom lever on a 2-3/4 inch backset, which matches the 9K's standard backset if you are mixing them in one building.
13) Does the BEST 9K Intruder lever need power or wiring at the door?
No. It is a fully mechanical cylindrical lock, no electrification, no transfer hinge, no power supply. Lockdown happens with a key at the door and keeps working when the building loses power. If you do want an electrified cylindrical lever on the same opening, the Corbin Russwin CL33903 is a Grade 1 fail safe unit running 12VAC/DC for 1-3/4 to 2 inch doors.
14) For a school corridor or office door that does not need lockdown, what Grade 1 lever can be used instead of the BEST 9K intruder?
For openings that only need free passage, the Falcon K101 is a Grade 1 heavy duty non-handed passage cylindrical lock, fire rated, for doors 1-3/8 inch to 2-1/4 inch, and the Corbin Russwin CL3110 is a Grade 1 vandal resistant passage lever for 1-3/4 inch to 2 inch doors. Neither is keyed. The BEST 9K intruder is a keyed double-cylinder lock, so it is the choice only where key control and emergency locking are part of the spec.
15) What is a lower-cost alternative to the BEST 9K intruder lever for a secured storage or utility door?
Where the door only needs to stay locked against the corridor, the Cal-Royal AG05 is a Grade 2 storeroom lever with a deadlocking latchbolt for doors 1-3/8 inch to 1-3/4 inch, and the Hager 2580 is a Grade 2 storeroom cylindrical lock with the Withnell lever for 1-3/8 inch to 2 inch doors. Both are single-cylinder storeroom function. The BEST 9K intruder is Grade 1 heavy duty and keyed on both sides for emergency lockdown, so the storeroom locks trade the inside key control and the higher grade for a simpler secured-door application.
16) Can an electrified cylindrical lever replace the BEST 9K intruder lock for access control?
They solve different problems. The Corbin Russwin CL33903 is a Grade 1 fail safe electrified cylindrical lever running on 12VAC/DC for doors 1-3/4 inch to 2 inch, so it is released from an access control system. The BEST 9K intruder is a mechanical lock with no electronics, secured by key from either lever. If the specification calls for credential-based release tied to a panel, the electrified lever is the right family; if it calls for a teacher to lock the door by key during an event with no power dependency, the 9K is.
17) Would an asylum or institution function lock work in place of the BEST 9K intruder lever?
Only if the intent is permanent key control on both sides. The Dexter C1000 asylum lock (DEX-C1000-ASYL) is a Grade 1 F87 cylindrical lock for doors 1-3/8 inch to 2 inch, and the Arrow MK33-BD-CS is a heavy duty asylum knob lock with a conventional Schlage C keyway cylinder. Asylum function keeps both levers locked at all times so a key is needed to enter or exit. The BEST 9K intruder is an F11 function where either lever can be locked or unlocked by key and the levers otherwise operate freely, which is what makes it suitable for an occupied classroom.
18) Is a keypad lever lock an option instead of the BEST 9K intruder for a classroom?
A mechanical keypad set such as the Lockey 1150 covers doors 1-1/8 inch to 2 inch with passage function and double combination entry, and the Delaney LP250 is a Grade 2 electronic keypad leverlock. Those give code-based entry, not the instant key-turn lockdown from inside the room that the BEST 9K intruder provides through its double-cylinder function and visual indicator. For a room where the priority is securing the door quickly during an incident, the keypad sets are not an equivalent.
19) What matching lever should be ordered for the non-locking doors alongside BEST 9K intruder locks?
Within a Grade 1 program, the Falcon T101 is a heavy duty Grade 1 cylindrical passage lever with pressure release technology and the Design Hardware X75 is a Grade 1 passage lever lockset with a flat lever for 1-3/4 inch doors. Either keeps the passage openings at the same grade as the BEST 9K intruder, which is Grade 1 heavy duty. Lever style and finish will not visually match across brands, so if appearance matters across a corridor the 9K is also offered in passage-side trims in the same finishes it lists, including 626 satin chrome and 630-family options such as 619 satin nickel.
20) Are residential-grade levers like Kwikset or Baldwin an acceptable substitute for the BEST 9K intruder lock?
Not for a commercial opening. The Kwikset 200BRNL Breton is a Grade 3 passage lever for 1-3/8 inch to 1-3/4 inch doors and the Baldwin Estate 5103 is offered in passage, privacy and half dummy functions. None of those are keyed on both sides or built to commercial duty. The BEST 9K intruder is a commercial Grade 1 heavy duty cylindrical lock on corrosion-treated steel with a solid brass 9/16 inch throw latch and hardened steel through-bolt studs.
How fast can I get the BEST 9K37IN15CSTK626 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 BEST 9K37IN15CSTK626 come with a warranty?
Absolutely. The BEST 9K37IN15CSTK626 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 BEST 9K37IN15CSTK626?
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 BEST 9K37IN15CSTK626 from ZenSupply?
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