• bitting code — the code needed to duplicate a key WITHOUT physically tracing it
• key gauge — how you find out an existing key's code
• code card — sort of a printed version of a key gauge?
  • there's some online. LockCodes.com requires a subscription, but still comes recommended
• ways to make a key from the bitting code:
  • key punch (they even have a handheld version that can make keys on the run)
  • file + vernier calliper
• key level
  • CK — change key — usually only opens one lock
  • MK — master key
  • GMK — grand master key
  • GGMK — great grand master key
  • GGGMK — great great grand master key

KW1 - Kwikset

• bitting code range
  • 5 or 6 pins
  • each pin can be value 1 through 6
• code
  • 1 = 0.328"
  • 2 = 0.305"
  • 3 = 0.282"
  • 4 = 0.259"
  • 5 = 0.236"
  • 6 = 0.213"
  • 7 = 0.190"

SC1 - Schlage

• bitting code range
  • 5 or 6 pins
  • each pin can be value 0 through 9

Arrow Lock

• code
  • 0 = 0.320"
  • 1 = 0.306"
  • 2 = 0.292"
  • 3 = 0.278"
  • 4 = 0.264"
  • 5 = 0.250"
  • 6 = 0.236"
  • 7 = 0.222"
  • 8 = 0.208"
  • 9 = 0.194"

other

• telephoto key decoding, how cool