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Quick Verdict

A mechanical push button lock (cipher lock) needs no power, no wiring and no batteries. One code, set and changed on the keypad, opens the door. Pick the family by door prep first, then by function. Cylindrical prep (ASA 161 bore): Simplex 1000 knob (1011, 1012) or the L-series lever (LL1011, LR1011). Same bore with a key override: LR1021S, LR1021R, LR1041C, or the 5000 series (5021). Aluminum storefront with an Adams Rite deadlatch: 3000 series (3001, 3002). Mortise prep: 8100 series (LR8146B). Exit device doors: LLP1010, LLP1020B, 5010 exit trims. Then match handing (LL is LH/LHR, LR is RH/RHR), backset (2-3/4" on most, 2-3/8" on the 1012 and LL1012) and the core brand on the key override. Pricing runs from about $279 (3001) to about $711 (LR8146B) at NLS.

How does a mechanical push button door lock work without power, and who buys it?

The lock is a purely mechanical combination device. The keypad buttons drive an internal code mechanism, and entering the correct sequence lets the lever or knob retract the latch. There is no electronics to fail, no battery to replace and no cabling to pull, which is the reason these locks sit on doors where running power is impractical or where the owner does not want a credential database.

Simplex pushbutton locks use a single access code, programmed from the keypad without removing the lock from the door. The Simplex 1000 knob and L-series lever locks are finished with vandal resistant, solid metal pushbuttons, and the lever versions carry fixed ADA-compliant levers. Several models are D.O.D. Compliant 5220.22M for supplemental access control and are weather resistant, with a 3-hour UL/ULC fire rating on "A" labeled doors (verify the label of the specific door).

Typical buyers: property managers (mechanical rooms, roof access, back-of-house doors), schools and municipalities (equipment rooms), hospitality (staff corridors), contractors who need a keyless lock that survives a construction schedule, and locksmiths who replace worn units on existing doors. The limitation is the same for every model: one code for all users, no audit trail, no per-user revocation. When you need those, step up to electronics. The decision between mechanical keypads, electronic keypads and proximity is covered in keypad vs proximity entry for doors, and the Alarm Lock and Schlage electronic alternatives are compared against Simplex in Alarm Lock DL2700 vs Schlage FE595 vs Kaba Simplex.

The families below are grouped in the mechanical pushbutton lock categories at NLS.

Which Kaba Simplex family fits which door?

The families map to door preparation. Match the prep first and the model number narrows quickly.

Family	Model examples	Door type	Functions
1000 knob	1011 (2-3/4" backset), 1012 (2-3/8" backset)	Wood or metal door, cylindrical (ASA 161) prep	Combination entry only, no key override
1000 lever (L series)	LL1011, LL1012 (LH/LHR), LR1011 (RH/RHR)	Wood or metal door, cylindrical (ASA 161) prep	Combination entry only
1000 lever with key override	LR1021S, LR1021R, LR1041C	Cylindrical prep	Combination entry plus key override; LR1041C adds passage
5000 lever	5021XSWL	Cylindrical prep	Combination entry with key override (K-I-L, Kaba cylinder, Schlage C keyway)
3000 narrow stile	3001, 3002	Aluminum storefront with Adams Rite 4510/4710/4910 mortise latch	Entry, key override, passage, lockout, thumbturn
8100 mortise	LR8146B	Standard (86) mortise prep	Entry, key override, passage, lockout
Exit trim	LLP1010, LLP1020B, 5010CWL	Doors with a rim exit device	Entry only (LLP1010) or entry plus key override (LLP1020B, 5010CWL)

The 1000 series knob locks are specified to ANSI A156.2 Grade 1 per the product data, with an all-metal cylindrical housing and cast copper fixed knobs. Door thickness range on the cylindrical models is 1-3/8" to 2-1/4". The L-series levers recommend a minimum stile of 5", which is the reason they do not go on aluminum storefront stiles. For those, use the 3000 series.

Two lever examples: the Kaba Simplex LL1011 pushbutton lock is the entry-only left-hand model, and the Kaba Simplex LR1021S with key override is the right-hand model that takes a Schlage LFIC.

What are the Simplex 5000 and 3000 series, and when do I order them?

The 5000 series is the field-friendly cylindrical lever. The 5021XSWL ships with a Kaba cylinder in a Schlage "C" keyway (K-I-L, key-in-lever), a 2-3/4" backset and a 1/2" latch. It is non-handed and pre-assembled for left-hand doors, and the handing is changed in the field. That is the difference from the 1000 lever line, which is factory-handed and not field reversible. Combination changes are made from the exterior. The 5010CWL is the exit device trim in the same family, with a Winston lever and Corbin Russwin 6 or 7-pin LFIC prep (core not included). See the Simplex 5000 series category for the full list.

The 3000 series is the narrow stile lock for aluminum storefront. It drives an Adams Rite 4510/4710/4910 mortise latch and offers entry, key override, passage and lockout with a clutch-protected fixed thumbturn on the inside. The 3002 adds a cylinder guard to the 3001. The key override accepts Maximum Security (MS) mortise cylinders, which means you can run it on an existing master-keyed system. The Simplex 3001 narrow stile lock with thumbturn is about $279 at NLS, and the browsable group is the Simplex 3000 narrow stile category. The model numbers 3010, 3020, 3030 and 3040 on the product page distinguish handing and backset (31/32", 1-1/8" or 1-1/2"), so confirm the stile geometry before ordering.

The 8100 series is the mortise version. The Kaba Simplex LR8146B mortise combination lock uses a 3/4" two-piece anti-friction latch, accepts a Best small format core (core not included), and offers combination entry, key override, passage and lockout. It is about $711 at NLS and is factory-handed (left hand reverse as listed). The group is in the Simplex 8100 mortise category.

Which models accept Best SFIC, Schlage, Sargent or Corbin LFIC?

The key override uses an interchangeable core, and Simplex builds separate models per core brand. Order the model, not the core: every one of these ships "less core."

Model	Override / core accepted	Handing
LR1021S	Schlage 6-pin LFIC prep	RH / RHR
LR1021R	Sargent 6-pin LFIC prep	RH / RHR
LR1041C	Corbin Russwin 6-pin LFIC prep, with passage	RH / RHR
LR8146B	Best SFIC (6/7-pin prep), mortise	Left hand reverse, factory-handed
LLP1020B	SFIC 6/7-pin prep, exit trim	LHR
5010CWL	Corbin Russwin 6 or 7-pin LFIC prep, exit trim	Non-handed, left-hand pre-assembly, changed in the field
5021XSWL	Kaba cylinder, Schlage C keyway (included)	Non-handed, left-hand pre-assembly, changed in the field
3001 / 3002	MS mortise cylinder	Non-handed lock, drive assembly factory-handed

The practical rule: use the core brand already running the building's master key system. The mix of formats (small format versus large format) and how they interchange is a separate question covered in SFIC vs LFIC interchangeable cores explained. For the key blanks that match each brand's keyway, see commercial key blanks by brand.

How do I get handing and backset right?

Simplex lever locks are factory-handed. The L-series naming gives it away: LL1011 and LL1012 are left hand / left hand reverse, and LR1011, LR1021S, LR1021R and LR1041C are right hand / right hand reverse. Stand outside the door, look at the hinges, and match the letter. If you order the wrong hand on a 1000 series lever, you cannot swap it in the field. The LLP1010 and LLP1020B exit trims are LHR and also not field reversible.

The knob models differ: the 1011 and 1012 knob locks are described as reversible for left-hand doors. The 5000 series (5021XSWL, 5010CWL) ships pre-assembled for left-hand doors and is changed in the field.

Backset: the common cylindrical backset is 2-3/4" (70 mm). The 1012 knob and LL1012 lever are the 2-3/8" (60 mm) variants. Measure from the door edge to the center of the cross bore before ordering. Both sizes use ASA 161 door preparation with additional through holes. The standard latch is 1/2" throw with a 3/4" throw optional on the lever line.

Combination entry only, passage or key override: which function for which room?

Entry only (1011, 1012, LL1011, LR1011, LLP1010): the cheapest and cleanest option for rooms where anyone with the code is allowed and a locksmith can reset the code by tool. The 1012 is about $461 at NLS. There is no key path, so a forgotten code means working with the combination change tool or the manufacturer's procedure. Do not choose it for a room that emergency responders must open without a code.

Entry with key override (LR1021S, LR1021R, 5021XSWL, LLP1020B): the key gives management and responders a path that does not depend on the code. This is the default for mechanical rooms, electrical closets and back-of-house doors.

Passage and lockout (LR1041C, 3001, 3002, LR8146B): passage lets the door be used without the code, activated from the inside with a thumbturn or key. Lockout disables the code entirely so only the key opens the door. This suits spaces that are open during business hours and secured after, such as retail back rooms or a shared office suite.

For exit devices with a pushbutton trim, the exit device may be dogged without affecting the trim. The exterior trim only controls the outside entry, egress stays free. The Kaba Simplex LLP1020B exit trim is the SFIC version with key override. Confirm the exit device brand on the compatibility list in the product data. For the Adams Rite narrow stile devices used on aluminum doors, see Adams Rite exit devices 8800, 8400, 8600 and 8700.

If the same opening also has an electric lock, the Securitron EEB2 emergency exit button is the backup release required when a motion sensor handles exit. That is an electrified setup, not a Simplex part.

Common mistakes

1. Ordering the wrong hand on a factory-handed lever. LL is LH/LHR, LR is RH/RHR, and the 1000 series lever cannot be reversed in the field.
2. Mixing up backsets. The default is 2-3/4". The 1012 and LL1012 are 2-3/8". Measure the existing bore.
3. Putting an L-series lever on a narrow aluminum stile. The L-series recommends a 5" minimum stile. Use the 3000 series for storefront.
4. Ordering the core with the lock and expecting it in the box. The key override models ship less core. Order the core separately to match the building's keying.
5. Choosing the wrong core brand. LR1021S is Schlage, LR1021R is Sargent, LR1041C is Corbin Russwin, LR8146B is Best SFIC.
6. Buying entry only where a responder needs a key path. Specify key override on any room that needs emergency access.
7. Leaving the default code in place. Change the code at install, and again whenever staff turnover warrants it.

FAQ

What is the difference between a cipher lock and a mechanical push button lock? In the field they are the same product: a keypad lock that opens with a code and needs no power. Simplex pushbutton locks are the standard commercial version, with a single code set from the keypad.

Do Simplex push button locks need batteries or wiring? No. The 1000, 3000, 5000 and 8100 series are fully mechanical, with no battery and no wiring. That is the main reason to choose them over electronic keypads.

Can a Simplex lock keep a master-keyed system? Yes, on the key override models. Choose the model that accepts the building's core brand (Schlage, Sargent, Corbin Russwin LFIC or Best SFIC) or the MS mortise cylinder on the 3000 series.

Which Simplex model fits an aluminum storefront door? The 3000 series (3001, 3002), which drives an Adams Rite 4510, 4710 or 4910 mortise latch. The 3002 adds a cylinder guard.

Is there a version for doors with panic hardware? Yes. The LLP1010, LLP1020B and 5010CWL are exit device trims that give exterior access by code while the exit device keeps free egress.

Next step

Send the door prep, handing, backset and core brand to the quote desk at /get-a-quote/ and we will confirm the exact Simplex model. Government and municipal buyers can submit a PO at /submit-a-gov-po/. Stock orders placed before 3:00 p.m. EST ship same day, and ground shipping is free on orders of $450 and up. For a direct answer, call 718-814-6300.