BEST 6K Series Office/Entry Fu...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$391.00
$283.25
BEST BEST 6K Series - Office/Entry (AB) Function Grade 2 Single Cylinder Knob Locks, SFIC Less Core BEST-6K-AB

BEST 6K Series Office/Entry Function Grade 2 Single Cylinder Knob Lock with SFIC Core

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Model: 6K37AB4KSTK626
$391.00
$283.25
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$391.00
$283.25
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BEST 6K Series Office/Entry Function Grade 2 Single Cylinder Knob Lock with SFIC Core

Professional Grade 2 Cylindrical Lock Solution

The BEST 6K Series knob lock delivers reliable performance for standard traffic commercial applications with Grade 2 ANSI certification. This single cylinder knob lock features BEST interchangeable core technology for quick rekeying, brass and bronze construction with corrosion-treated internal steel mechanisms, and accommodates door thickness from 1 3/8" to 1 7/8". UL listed for 3-hour fire rating and BHMA certified to A156.2 Series 4000 Grade 2 standards.

Professional Features & Benefits

  • Door Compatibility: Accommodates door thickness from 1 3/8" to 1 7/8" with threaded outside rose adjustment for precise fit.
  • Quick Rekeying System: BEST interchangeable core allows rapid key changes without disassembly for enhanced security management.
  • Durable Construction: Brass and bronze component parts with corrosion-treated internal steel mechanisms for long-term reliability.
  • Concealed Mounting: Snap-on inside rose design eliminates exposed mounting screws for clean appearance and tamper resistance.
  • Fire Rating Certification: UL listed for use on 3-hour A label single doors up to 4' x 8' for code compliance.
  • Grade 2 Performance: BHMA certified to A156.2 Series 4000 Grade 2 standards exceeding minimum requirements for commercial applications.
  • Reversible Operation: Lockset reversible for either hand of door without removing keyed knob for installation flexibility.
  • Deadlocking Security: 1/2" throw deadlocking latch provides positive engagement for enhanced security.

Technical Specifications

  • Commercial/Residential: Commercial
  • Department: Door Hardware
  • Duty Level: Medium Duty
  • Electronic: No
  • Grade: Grade 2
  • Handle Type: Knob
  • Keyed: No
  • Keyed Function: Single Cylinder
  • Product Attribute: Cylindrical Locks
  • Product Category: Mechanical Locks
  • Product Function: Office
  • Product Group: Mechanical Locks
  • Product Subgroup: Bored Locksets
  • Product Type: Knobsets
  • Series: 6K Series
  • Standard Latch: 1/2" Throw
  • Standard Strike: 2-3/4" x 1-1/8" with Curved Lip
  • Subcategory: Bored Locksets

Installation & Operation

  1. Review manufacturer specifications and verify door preparation requirements including door thickness from 1 3/8" to 1 7/8", 2 1/8" diameter bore for lock housing, and 1" or 7/8" diameter for latch tube.
  2. Use manufacturer-provided templates to mark mounting hole locations accurately on door and frame surfaces for proper alignment.
  3. Prepare door by drilling required 2 1/8" bore hole and latch tube opening according to backset specifications (2 3/8" for 62K, 2 3/4" for 63K, 3 3/4" for 64K, or 5" for 65K Series).
  4. Install latch assembly and secure the knob lock to door using threaded outside rose adjustment for proper door thickness accommodation.
  5. Adjust snap-on inside rose for concealed mounting and verify keyed knob removal requires core removal for security.
  6. Test lockset operation to verify proper function, deadlocking latch engagement, and reversible operation. Refer to manufacturer documentation for complete installation details and troubleshooting.

Professional Applications

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

Why Choose BEST Quality?

BEST 6K Series knob locks deliver professional-grade reliability with brass and bronze construction and corrosion-treated internal mechanisms rated to exceed ANSI Grade 2 standards. UL listed for 3-hour fire rating and BHMA certified for demanding commercial applications. Engineered for standard traffic applications where dependable performance and quick rekeying capability are essential.

Product Specs

Series:
6K Series
Grade:
Grade 2
Duty Level:
Medium Duty
Keyed Function:
Single Cylinder
Standard Latch:
1/2" Throw
Standard Strike:
2-3/4" x 1-1/8" with Curved Lip
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
Tags:
best brand door handles, best lock door handle
Product Function:
Office
Product Category:
Mechanical Locks
Department:
Door Hardware

BEST 6K37AB4KSTK626 – Frequently Asked Questions

1) Will the BEST 6K knob lock fit a 1-3/4 inch commercial door?
Yes. The 6K Series knob lock covers door thickness from 1-3/8 inch through 1-7/8 inch, so a standard 1-3/4 inch commercial door sits in the middle of the range, and a 1-3/8 inch older interior door works too. The outside rose is threaded, so you dial the fit to the actual door rather than swapping parts.
2) Which backset do I order for a BEST 6K knob lock, and does it change the door prep?
Four backsets are offered: 2-3/8 inch, 2-3/4 inch, 3-3/4 inch and 5 inch. The two common ones are 2-3/8 and 2-3/4; the 3-3/4 and 5 inch options exist for wide-stile or unusual openings. The bore is 2-1/8 inch diameter regardless, with a 1 inch or 7/8 inch latch tube hole, so the backset only moves where that latch bore lands from the door edge. Measure from the door edge to the center of the existing 2-1/8 inch hole and match it.
3) Does the office function BEST 6K knob lock latch into a standard commercial strike?
The latch is a 1/2 inch throw deadlocking latch, and the lock ships against a 2-3/4 x 1-1/8 inch curved lip strike. If your frame is already prepped for an ANSI strike, order the S3 ANSI strike option instead of the standard STK strike so the lock drops into the existing frame cutout without refiling it.
4) Does a BEST 6K office function lock come with a core, or do I have to order one?
It ships less core. The 6K takes a BEST small format interchangeable core, and you supply that separately, keyed to your existing system. That is the point of the design for a property manager or facility with an SFIC master key setup: the housing goes in once, and rekeying later is a core swap with a control key, no disassembly of the lock. Note the keyed knob cannot be pulled without removing the core first.
5) Is a Grade 2 knob lock enough for a commercial office corridor, or do I need Grade 1?
The BEST 6K is BHMA certified to A156.2 Series 4000 Grade 2 and is a medium duty commercial lock. That suits office suites, tenant doors, back-of-house and standard traffic openings. For a high-traffic entry, a stairwell, or a door that gets abused, step up to a Grade 1 cylindrical, such as the Falcon X101 heavy duty Grade 1 knobset, which also takes an interchangeable core, or the Sargent 8XG04 Grade 1 storeroom knob lock on a 2-3/4 inch backset.
6) What is the difference between the BEST 6K and a keyed knob lock like the Dexter C2000 or Corbin Russwin CK4851?
The difference is the cylinder. The 6K uses a BEST small format interchangeable core supplied separately, so a facility with a master key system rekeys by pulling cores. The Dexter C2000 entry/office knob lock is a Grade 2 keyed cylindrical for 1-3/8 to 1-3/4 inch doors, and the Corbin Russwin CK4851 entrance/office knob lock uses a conventional cylinder and covers 1-3/8 to 2 inch doors. Both of those are simpler to buy because the cylinder comes in the box; neither gives you core-swap rekeying. If you do not run an SFIC system, a conventional cylinder lock is the less complicated order.
7) Which knob locks besides the BEST 6K are fire rated for a labeled door?
The Falcon W101 Grade 2 passage/closet knob lock and the Falcon X101 Grade 1 passage knobset both carry a fire rating. The BEST 6K is UL listed for use on 3 hour A label single doors up to 4 feet by 8 feet. The two Falcon options are non-keyed functions, so on a labeled door that also has to lock, the 6K office function is the keyed one of the three.
8) Which knob lock should be used on an opening that needs Grade 1 instead of Grade 2?
The Sargent 8XG04 is a Grade 1 heavy duty storeroom/closet single cylinder knob lock with a 2-3/4 inch backset. For a non-keyed Grade 1 opening, the Falcon X101 is a heavy duty Grade 1 cylindrical passage knobset with an interchangeable core, fire rated, covering doors 1-3/8 inch to 2-1/4 inch, and the Schlage D10S is a Grade 1 heavy duty passage latch with an Orbit knob. The BEST 6K carries a Grade 2 medium duty rating, so on a high traffic opening specified at Grade 1 one of those is the substitution.
9) What knob lock locks from the outside at all times instead of using office function?
Office function lets the inside push button hold the outside knob unlocked. When the outside knob must stay locked and key-only, the Sargent 6G04 is a Grade 2 standard duty storeroom/closet knob lock with a single cylinder, and the Sargent 8XG04 is the Grade 1 heavy duty storeroom/closet version with a 2-3/4 inch backset. For a classroom opening keyed from the outside only, the Dexter C2000 classroom ball knob lock is Grade 2 for doors 1-3/8 inch to 1-3/4 inch.
10) Which knob locks fit doors thicker than 1-7/8 inch?
The BEST 6K accommodates door thickness from 1 3/8 inch to 1 7/8 inch. For a thicker door, the Falcon X101 Grade 1 passage knobset with interchangeable core covers 1-3/8 inch to 2-1/4 inch, and the Corbin Russwin CK4310 Grade 1 passage/closet lock and CK4851 entrance/office lock both cover 1-3/8 inch to 2 inch. The Deltana 3381 Egg Knob entry and 6171 Round Knob entry also take doors to 2 inch.
11) What knob lock covers a 5 inch backset opening?
The BEST 6K is offered in 2-3/8 inch, 2-3/4 inch, 3-3/4 inch and 5 inch backsets. Among the comparable knob locks, the stated backsets are fixed: the Falcon W101 passage/closet knob and the Sargent 8XG04 storeroom lock are 2-3/4 inch, and the Baldwin Estate 5000 Baltimore passage and privacy knobs are 2-3/8 inch. For a wide stile or a door prepped past 3-3/4 inch, the 6K backset range is the one that reaches it.
12) What does office/entry function mean on a BEST 6K knob lock day to day?
Office/entry is the function for a door someone wants to leave open during business hours and secure when they leave. The outside knob locks by pushbutton or turn control from inside, and the key retracts the latch from outside; the inside knob is always free for egress. It is a single cylinder lock, so there is no key required on the inside face. If you instead need a door that stays locked outside at all times and never unlocks by button, that is a storeroom function, not this one.
13) Do I have to specify handing when ordering a BEST 6K knob lock?
No handing to specify. The 6K lockset is reversible for either hand of door, and you can reverse it without pulling the keyed knob. One part number covers left and right hand openings, which is why it works well as a stocked spare across a building.
14) What rose size should I pick to cover the old paint ring or an oversized hole?
Three rose options are offered on the 6K: the standard K 3 inch, a smaller 2-9/16 inch, and a 3-3/8 inch. Go to the 3-3/8 inch rose when the previous lock left a larger footprint or an overbored hole you need hidden. The 2-9/16 inch is the tighter look for narrower stiles. The inside rose snaps on with no exposed screws either way.
15) What finishes does the BEST 6K knob lock come in, and which matches existing brass or chrome hardware?
Seven finishes: 605 bright brass, 606 satin brass, 611 bright bronze, 612 satin bronze, 613 satin bronze oil-rubbed, 625 bright chrome and 626 satin chrome. If you are matching a building already standardized on the usual commercial finish, that is 626 satin chrome. For older brass-trimmed buildings, 606 satin brass. The finish codes are BHMA numbers, so a 626 here matches a 626 on other manufacturers' hardware in the same opening.
16) Will a BEST 6K knob lock replace a residential entry knob like a Kwikset 400P?
Not a straight swap in most cases. The Kwikset 400P-CP keyed entry knob is a Grade 3 residential lock for 1-3/8 to 1-3/4 inch doors with its own adjustable latch and round corner strike. The 6K is a Grade 2 commercial lock that ships less core and uses a 2-3/4 x 1-1/8 inch curved lip strike or an ANSI strike, so the frame prep and the keying are both different. If the existing frame has a small round corner strike cut, you will be modifying it. Where the goal is just an in-kind residential replacement, stay with a residential entry knob.
17) How do I tell which BEST 6K model number matches my backset?
The model number carries the backset. 62K is the 2-3/8 inch backset, 63K is 2-3/4 inch, 64K is 3-3/4 inch and 65K is 5 inch, all within the 6K Series. So if a drawing calls for a 63K office function lock, you are ordering the 2-3/4 inch backset version of this lock.
18) What is a simpler knob lock for an opening that does not need to be keyed?
Non-keyed knobs in the same Grade 2 cylindrical class include the Corbin Russwin CK4410 passage/closet lock with a Global knob for doors 1-3/8 inch to 1-3/4 inch, the Falcon W101 medium duty fire rated passage/closet knob lock with a 2-3/4 inch backset, the Dexter C2000 passage ball knob, and the Arrow MK01 and RK01 passage knob locks, both Grade 2 for doors 1-3/8 inch to 1-3/4 inch. For bed and bath openings the Dexter C2000 privacy ball knob is the Grade 2 equivalent. The BEST 6K is a keyed office function knob, so on corridor, closet, or bathroom doors these non-keyed functions do the job without a core.
19) Are Grade 3 keyed entry knobs an equivalent to the BEST 6K office function lock?
They are a different rating class. The Cal-Royal BER00 entrance/office knob lock is Grade 3 with a Kwikset keyway for doors 1-3/8 inch to 1-3/4 inch, the Pamex FTF Baron entrance/office knob lockset is Grade 3, the Kwikset 400P-CP Polo keyed entry knob is Grade 3, the Master Lock BC01 biscuit knob keyed entry is Grade 3, and the Callan Canova and Santo entrance knobsets are Grade 3. The BEST 6K is certified Grade 2. Where a spec sheet calls for Grade 2 commercial, a Grade 3 knob does not meet it; where the opening is light residential-style traffic, those are the alternative.
20) What knob products look like a substitute for a keyed cylindrical lock but will not latch or lock a door?
Dummy trim has no latch and no cylinder. The Schlage A170 single dummy trim, the Bravura Biloxi dummy knobset, the Omnia 434/0, 442/00 and 458/0 single dummy knob latchsets, and the Emtek Hammered Egg, Georgetown and Providence dummy pairs are all dummy function. The Sargent 78-2875 is an outside knob only with B design, and the Sargent 28C-KNOB is exit device trim rather than a bored lock. The BEST 6K is a keyed single cylinder knob lock with a 1/2 inch throw deadlocking latch, so none of those replace it on an opening that has to latch.
21) Is there a knob lock that works without keys for a door that a crew shares?
The Lockey 3830 is a mechanical keyless combination knob lock with an auto-locking passage function, for doors 1 3/16 inch to 2 inch. It is opened by a code rather than a key. The BEST 6K is a keyed single cylinder office function knob taking an interchangeable core, so the choice is between issuing keys against a keying system and issuing a code that anyone with the combination can use.
22) What is the BEST 6K knob lock made of, and will it hold up in a humid or coastal building?
Component parts are brass and bronze, with the internal steel mechanisms corrosion treated. That combination is what carries it through healthcare, hospitality and industrial openings where a plated pot metal knob would pit. It is a mechanical lock with no electronics, so there is nothing in it to fail from moisture in a panel.
23) What is the alternative for a decorative knob on an interior door in a hospitality or residential setting?
Decorative knobsets in the set include the Baldwin Estate 5077 Bethpage privacy knob with R027 rose, the Baldwin Estate 5011 Colonial passage knob with 5058 rose, the Deltana 6112 St. Thomas privacy knob and 6901 Portland entry knob, the Emtek Porcelain knobs with threaded rod, and the Omnia 434/PA egg-shaped knob latchset in solid brass. The BEST 6K is a commercial Grade 2 knob lock finished in 605 bright brass through 626 satin chrome, which is the style range it offers instead.
How fast can I get the BEST 6K37AB4KSTK626 delivered?
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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 6K37AB4KSTK626 come with a warranty?
Absolutely. The BEST 6K37AB4KSTK626 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 6K37AB4KSTK626?
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