ALOA CAL cheat sheet

Pin tumbler lock: driver pins sit in the bible above the shear line; key pins sit in the plug below it; the plug rotates only when all pin splits align at the shear line.

Warded locks use fixed projections (wards) that block all but a matching key; they offer no pin-tumbler security and are bypassed by skeleton keys.

Lever tumbler locks gate on lever height: each lever must be lifted to the fence height set by its own cut before the bolt can retract.

Disc/detainer locks (e.g., Wafer and Abloy-style) rotate or lift rotating discs; the sidebar releases only when all discs align to a gate.

Standard pin-tumbler keyway designations (Kwikset KW1, Schlage SC1, Yale Y1) identify blade profile, not pinning; pinning is set by the key bitting chart.

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

A deadbolt throws a bolt with no spring latch; a latchbolt has a spring-loaded beveled bolt that retracts on contact with the strike.

ANSI/BHMA grade (1, 2, 3) rates cycle endurance and security; Grade 1 is the highest commercial rating, Grade 3 the lowest residential tier.

Shear line = the boundary between plug and shell; pin stacks must split exactly there or the plug will not turn; a single overlong driver pin binds the whole cylinder.

Binding order is set by manufacturing tolerance: the first pin to bind is the one with the tightest bore fit, so pick tension reveals the binding sequence, not the cut depth.

Cylinder pinning math: bottom pin + master wafer + driver pin must equal the chamber depth at the shear line for every shear combination.

Electronic access control: fail-safe locks unlock on power loss (life-safety egress); fail-secure locks stay locked on power loss (asset protection).

Request-to-exit (REX) devices and crash bars must release egress hardware independent of the access-control decision; code requires free egress at all times.

Electric strike types: fail-secure strikes stay locked without power; fail-safe strikes release without power; voltage (12/24 VDC) and duty rating must match the controller.

Battery-powered electronic locks degrade first at the motor/clutch; low-battery lockout is a designed behavior, not a fault, and should be tested on a schedule.

Lubrication rule: graphite is for dry pin-tumbler cylinders; oil and grease attract dust and gum up springs; silicone spray is preferred for sliding and plastic parts.

Door closer sweep and latch speeds are adjusted by separate valves; backcheck controls opening speed and must be set before sweep/latch tuning.

Key bitting depth is measured from the blade shoulder or tip per the manufacturer's spec; spacing is the distance between cut centers along the blade.

Root depth vs. shallowest cut: each key cut must be deep enough to clear the bottom pin yet shallow enough to lift the driver pin above the shear line.

A key's bitting is read tip-to-bow or bow-to-tip depending on the system; always confirm the direction against the manufacturer's bitting chart before cutting.

Macs (maximum adjacent cut specification) limit the depth difference between neighboring cuts so the key will not hang up on the pin stack.

First key / last key rules define the highest and lowest legal cuts in a system; any bitting outside that envelope is invalid.

Key duplication by code requires the original bitting record; duplicating by tracing an unknown key loses the code and risks an out-of-spec copy.

Blanks must match keyway profile and thickness; a blank that is too thick binds in the keyway; too thin causes wobble and wear.

Cutting a key: zero the machine on the blank shoulder, cut from the highest (shallowest) cut to the lowest, and deburr the blade before testing in the cylinder.

Master keying uses two-level pinning: each chamber holds a bottom pin, a master wafer, and a driver pin so the change key and master key each reach the shear line.

Total stack height (bottom + wafer + driver) must equal the chamber depth for every shear combination; if it does not, the cylinder will not key.

A master key system has levels: change keys (lowest), sub-master, master, grand master; each level must open its own set and all below it.

Cross-keying is when one change key opens another change's lock; it is a defect, not a feature, and must be eliminated during pinning.

Number of usable levels is limited by the number of pin depths and chamber count; two-level systems need at least two depths per chamber that do not conflict.

A master key bitting must be a valid key under the system's macs and first/last key rules for every lock it opens, not just the master cylinder.

Progression charts assign each change a unique bitting; a master key system must be documented so future changes do not collide.

Pinning a master cylinder: install bottom pin, then master wafer, then driver; verify with change key, master key, and a non-master key that should fail.

Verify authority before opening: photo ID plus proof of occupancy (lease, utility bill, or work order) for the address; document the interaction.

Never pick or bypass a lock for a customer who cannot prove ownership or authorized access; refer to the property owner or management.

Locksmiths are generally required to be licensed or registered in many jurisdictions; confirm local licensing before performing work.

Keep a service record: date, address, customer, work performed, parts used, and signature; this protects against liability and disputes.

Safety: eye protection when cutting keys or drilling; gloves when handling sharp burrs; do not disable egress hardware even temporarily without a plan to restore it.

Fire and life-safety codes require free egress; never install a lock or strike that prevents exit from the inside, regardless of customer request.

Customer data (key codes, access codes, alarm codes) is confidential; store it securely and never disclose it to third parties without authorization.

Charge and quote in writing; disclose parts, labor, and trip charges before work begins to avoid disputes and comply with consumer-protection rules.