🔑Keys

Tubular Keys

Invented by the Chicago Lock Company, typically 6-8 pins most commonly 7. Chicago Ace bitting goes 1-8, clockwise from the point of view of the lock (being a lock company). Unfortunately, there's a second bitting by GEM (who makes keys...) called Fort Lock which uses the exact same depths but is numbered 0-7 and goes clockwise from the point of view of the key. Fort Lock appears to be the typical bitting these days. Source.