BEST 8K Series Grade 1 Heavy D...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$971.00
$539.44
BEST BEST 8K Series - Corridor/Apartment Function (C) Double Cylinder Grade 1 Heavy Duty Knob Lock, SFIC Less Core BEST-8K-C

BEST 8K Series Grade 1 Heavy Duty Corridor Function Double Cylinder Knob Lock

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Model: 8K37C4ASTK626
$971.00
$539.44
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$971.00
$539.44
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BEST 8K Series Grade 1 Heavy Duty Corridor Function Double Cylinder Knob Lock

Premium Grade 1 Cylindrical Knob Lock for Heavy-Duty Commercial Applications

The BEST 8K Series Grade 1 Heavy Duty Corridor Function Double Cylinder Knob Lock delivers dependable security for high-traffic commercial applications. This premium cylindrical knob set features knobs machined from solid brass or bronze bar stock with a 2 1/8" diameter and 9/16" throw deadlocking latch. Designed with a 2 1/16" diameter chassis to fit standard 2 1/8" door holes, the 8K Series exceeds ANSI Grade 1 requirements for security and reliability in demanding commercial environments.

Professional Features & Benefits

  • Grade 1 Heavy-Duty Construction: Exceeds ANSI Grade 1 requirements with knobs machined from solid brass or bronze bar stock for exceptional durability in high-traffic applications.
  • Standard Door Compatibility: 2 1/16" diameter chassis fits standard 2 1/8" door holes with adjustable door thickness from 1 3/8" to 2" standard.
  • Enhanced Security Design: Cores must be removed before keyed knobs to deter break-in attempts, with snap-on inside rose featuring no exposed screws for additional attack resistance.
  • Premium Materials: Internal parts are brass or corrosion-treated steel with brass or bronze roses reinforced with steel liner for long-term reliability.
  • Smooth Operation: Steel retractor with low friction bearings and long bearing length in chassis provide smooth, wear-resistant operation throughout the lock’s service life.
  • Flexible Installation Options: 2 3/4" standard backset with 3 3/4" and 5" options available, plus multiple rose styles including round 3 3/4" diameter and 2 9/16" diameter options.
  • Quick Rekeying Capability: BEST interchangeable core system allows for economical rekeying without lock replacement.
  • Optional Security Features: Available with breakaway feature to prevent overpowering by wrench, knurled knob option for accessibility applications, and spin-free knob feature for key-only operation.

Technical Specifications

  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Door Hand Direction: Non-Handed
  • Duty Level: Heavy Duty
  • Electronic: No
  • Grade: Grade 1
  • Handle Type: Knob
  • Keyed: No
  • Keyed Function: Double Cylinder
  • PDF:8K Series Catalog: https://zensupply.com/content/pdf/best/8K-Series-Catalog.pdf
  • PDF:Service Manual for 8K Series: https://zensupply.com/content/pdf/best/4418820857627
  • Product Attribute: Cylindrical Locks
  • Product Category: Mechanical Locks
  • Product Function: Corridor/Dormitory
  • Product Group: Mechanical Locks
  • Product Subgroup: Bored Locksets
  • Product Type: Knobsets
  • Series: 8K Series
  • Subcategory: Bored Locksets

Installation & Operation

  1. Review manufacturer specifications and verify door preparation requirements including door thickness (1 3/8" to 2" standard), 2 1/8" bore hole, and 1" latch hole dimensions.
  2. Use manufacturer-provided templates to mark mounting hole locations accurately on door and frame surfaces for proper backset alignment (2 3/4" standard).
  3. Prepare door by drilling required 2 1/8" diameter hole for chassis and 1" hole in door edge for latch housing.
  4. Install latch assembly and secure knob set chassis to door with threaded roses, ensuring proper alignment and door thickness adjustment.
  5. Adjust knob operation for smooth function and verify 9/16" throw deadlocking latch engagement with strike plate.
  6. Test lock operation with interchangeable core installed to verify proper function and make final adjustments as needed. Refer to manufacturer documentation for complete installation details and troubleshooting.

Professional Applications

  • Government and Military Facilities
  • Commercial Office Buildings
  • Educational Institutions
  • Healthcare Facilities
  • Multi-Tenant Residential Properties
  • Industrial and Warehouse Facilities
  • High-Traffic Commercial Entrances

Why Choose BEST Quality?

BEST 8K Series knob locks deliver professional-grade reliability with solid brass or bronze construction and Grade 1 certification that exceeds ANSI requirements for security and durability. The premium workmanship includes corrosion-treated internal components and carefully designed mechanisms that ensure reliable performance in demanding commercial applications where dependable security is essential.

Product Specs

Series:
8K Series
Grade:
Grade 1
Duty Level:
Heavy Duty
Keyed Function:
Double Cylinder
Product Group:
Mechanical Locks
Product Subgroup:
Bored Locksets
Product Type:
Knobsets
Subcategory:
Bored Locksets
Keyed:
No
Electronic:
No
Commercial/Residential:
Commercial
Handle Type:
Knob
Product Attribute:
Cylindrical Locks
Product Function:
Corridor/Dormitory
Door Hand Direction:
Non-Handed
Product Category:
Mechanical Locks
Department:
Door Hardware

BEST 8K37C4ASTK626 – Frequently Asked Questions

1) What is a corridor function lock and how does it work?
Corridor function allows outside key entry at all times. Inside knob is always unlocked for free egress. The outside knob is locked except when operated by key. This function is ideal for apartment entries, office doors, and other spaces requiring controlled access with unrestricted exit.
2) What does SFIC less core mean for this lock?
SFIC stands for Small Format Interchangeable Core. This lock accepts SFIC cores but ships without the core installed. You must purchase and install a compatible SFIC core separately. This allows integration into existing master key systems and provides enhanced security through core interchangeability.
3) What door thickness does this Grade 1 lock accommodate?
Most commercial Grade 1 knob locks accommodate door thickness from 1-3/8" to 1-3/4" standard. Some models adjust for doors up to 2-1/4". Check the manufacturer template and specifications to verify compatibility with your specific door thickness before installation.
4) How do I determine the correct door handing for this lock?
Stand on the side of the door where the hinges are not visible. If hinges are on your right, it's right-handed. If on your left, it's left-handed. Most commercial knob locks are non-handed or field reversible. Verify the specific handing requirements with the manufacturer specifications.
5) What backset does this lock require?
Standard commercial locks typically use 2-3/4" backset. Some models offer adjustable backsets for 2-3/8" residential applications. Measure from the door edge to the center of the existing bore hole to determine your required backset. Verify compatibility before ordering.
6) What are the bore hole requirements for installation?
Standard commercial knob locks require a 2-1/8" bore hole through the door face and a 1" cross bore through the door edge. The cross bore must align precisely with the main bore. Use the manufacturer's template for exact measurements and drilling specifications.
7) Can this lock be used on fire-rated doors?
Fire-rated door applications require locks with specific fire ratings and approvals. Check if this model carries UL fire ratings and verify compliance with local fire codes. The lock installation must not compromise the door's fire rating. Consult fire safety codes for your specific application.
8) What grade rating does this lock carry?
This is specified as a Grade 1 lock, the highest ANSI/BHMA security and durability rating. Grade 1 locks undergo rigorous testing for cycle life, security, and finish durability. They're designed for high-traffic commercial applications and provide maximum security performance.
9) How do I maintain and adjust this commercial knob lock?
Lubricate the mechanism annually with graphite or approved lock lubricant. Check and tighten mounting screws periodically. Adjust latch alignment if the door sags or shifts. Clean exterior surfaces with mild soap and water. Avoid petroleum-based cleaners that can damage seals and finishes.
10) What tools are needed for installation?
Installation requires a drill with 2-1/8" hole saw for the main bore and 1" spade bit for the cross bore. You'll need a chisel set for mortising the latch and strike plates, screwdrivers, tape measure, and level. Use the manufacturer's template to ensure precise measurements and alignment.
11) Are there matching deadbolts available for this lock series?
Most commercial lock manufacturers offer coordinating deadbolts in matching finishes and key systems. Look for deadbolts from the same product series that accept SFIC cores. This ensures consistent appearance and allows integration into your master key system. Check our deadbolts section for compatible options.
12) What strike plate options work with this lock?
Commercial installations typically use heavy-duty strike plates with longer screws that penetrate the door frame studs. T-strike plates provide enhanced security for high-traffic applications. Box strikes accommodate doors with frame gaps. Match the strike plate to your frame type and security requirements.
How fast can I get the BEST 8K37C4ASTK626 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 8K37C4ASTK626 come with a warranty?
Absolutely. The BEST 8K37C4ASTK626 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 8K37C4ASTK626?
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 8K37C4ASTK626 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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