ALOA CML cheat sheet

Pin tumbler lock: driver pins sit in the bible above the shear line; key pins rest in the plug below it; the correct key lifts each pin stack so all breaks align at the shear line.

Pin stack height = key pin length + driver pin length + spring compression allowance; total stack must clear the bible bore when the correct key is inserted.

Standard pin tumbler master keying: a master key uses the deepest shear line, the change key the shallowest; the master wafer/pin occupies the difference (master pin length = shallow depth − deep depth).

Bottom-of-keyway (BOK) tension uses the plug's lower ledge; top-of-keyway (TOK) tension bears on the upper wards - TOK leaves more pick clearance on many keyways.

Key bitting depths are cut from the tip or shoulder per the manufacturer's spacing; depth increment is the difference between adjacent cut numbers (commonly ~0.015–0.025 in).

Warded locks are opened by passing a skeleton-type ward cut past fixed wards; they offer no pin-tumbler security and are rated by ward configuration, not pin count.

Lever tumbler locks: the fence must drop into all lever gates simultaneously; the number of levers sets the theoretical differs (2^levers with single-gate levers).

Cylinder plug diameter and keyway profile must match the lock series; a wrong-profile key blank will bind or fail to enter regardless of bitting.

Mortise lock handing: a beveled latch face and the lock body's latch orientation define left- or right-hand; reversing the latch (not the body) changes handing.

Backset is measured from the door edge (or face plate) to the center of the spindle/cylinder hole; common backsets are 2-3/8 in and 2-3/4 in.

Electric strike fail-safe = unlocked when unpowered (fire-code egress side); fail-secure = locked when unpowered - verify against life-safety requirements before specifying.

Access control: REX (request-to-exit) devices must release the lock for egress; delayed egress and electromagnetic locks require code-compliant release hardware.

Solenoid vs. motor-driven electronic locks: solenoids draw higher inrush current and are polarity-sensitive; motors are quieter and often use lower holding current.

Battery-powered electronic locks: low-battery warning thresholds and audit-trail retention are set in firmware; audit logs typically cap at a fixed number of events and overwrite oldest first.

Door closer sweep and latch speed valves are independent adjustments; backcheck controls opening speed and prevents door/wall damage - never fully close any valve.

Strike plate alignment: adjust strike lip depth and vertical position so the deadlatch (anti-shim) plunger clears the strike, preventing credit-card bypass.

Transponder keys: the chip (often an ID46/ID4D/etc. type) must be programmed to the immobilizer; cutting the mechanical blade alone will not start the vehicle.

Key generation workflow for many vehicles: obtain the key code or decode the lock, cut the blade, then program the transponder/chip and, if applicable, the remote (RKE) function.

All-keys-lost (AKL) procedures may require a security access (PIN/seed-key) step, an OBD programmer, or bench reading of the immobilizer module - capability varies by make/model/year.

VATS/PASS-Key systems use a resistor pellet in the key; the measured pellet resistance must fall within the vehicle's stored value range (±tolerance) for crank enable.

Transponder cloning vs. adding: cloning copies an existing chip's data to a clone chip; adding registers a new key as an additional key in the vehicle's memory (key count matters).

Remote head keys combine blade, transponder, and RKE transmitter; programming order is typically immobilizer first, then remote synchronization (often a door-lock/ignition sequence).

Key code systems: manufacturer codes map to bitting via a codebook or key machine software; verify cut key by test-fitting in the door and ignition before programming.

Safe rating labels (e.g., TL-15, TL-30) denote the tool-resistance test time in minutes against a defined tool set; higher numbers = longer resistance.

Group 2 vs. Group 1 combination locks: Group 2 uses a 3-number dial with a drive cam; Group 1 (and 1R) are higher-security, often with more precise tolerances and manipulation resistance.

Combination dialing: turn to the first number in the specified direction, pass the second number the required number of times, land the third, then turn to open - direction and pass counts are lock-specific.

Safe combination change usually requires the existing combination plus the change key or a reset procedure; record the new combination and verify before closing the door.

Relockers are spring-loaded bolts that fire if the lock is attacked (thermal or punch); they can lock out a safe after a failed break-in and require drilling/servicing to reset.

Manipulation resistance: Group 1 locks resist dial manipulation better than Group 2; contact-point and wheel-pack analysis is the basis of manipulation technique.

Fire ratings (e.g., 350°F/1-hour, 2-hour) address internal temperature limits for media; burglary ratings (TL) address tool attack - the two are independent certifications.

Proof of authorization: for vehicle or building entry, verify identity and right to access (registration, ID, work order, or property-manager authorization) before beginning work.

Liability and licensing: many jurisdictions require locksmith licensing, bonding, and/or insurance; performing work outside licensure can void coverage and create legal exposure.

Written estimates and invoices should itemize labor, parts, trip charges, and any emergency premium; get customer approval before non-emergency add-on work.

Key control and data handling: customer key codes, master-key charts, and access credentials are sensitive; store and transmit them securely and return or destroy per agreement.

Master key system delivery includes a signed chart and restricted-keyway authorization; the customer owns the system, and the locksmith retains no unauthorized copies.

Payment and pricing: emergency/after-hours rates, service-call minimums, and disposal of old cylinders/keys should be disclosed up front to avoid disputes.

Recordkeeping: retain job records (authorization, work performed, parts used) per local retention rules; these support warranty claims and liability defense.