Replacing keys for an existing lock is difficult
Lock bits, also known as blades, are specifically cut to fit a lock. Depending on the lock mechanism this can be complex.
Unfortunately knowing the manufacturer and model number of the lock does not help in locating a key to fit an antique lock.
Cutting the bit/blade, to turn the lock mechanism, often requires the skills of a locksmith.
Before choosing a key blank:
Determine lock-pin diameter This measurement is critical as key-barrel must slide over lock pin.
The key-bit must be sized correctly to move the lock-bolt .
Profile of key-bit varies according to individual locks.
Some locks are easily turned with a simple un-notched blade
Other locks require a key bit with one notch to lock or unlock
Many locks require a key cut with 2 notches: one notch locks the lock the other notch unlocks the lock
Some locks, made with spring-loaded levers, also require 2 notches however they also must be different sizes. This type of key is difficult to reproduce
Selecting Keyhole Covers - Escutcheons
For accurate fit:
- Measure keyhole height in keyhole cover
- Measure key-end height, height of key-bit
- Compare above determined measurements, to interior keyhole measurements, of the desired keyhole cover