azz19 wrote:Why no size 1 master pins?
Is there a problem with having size 1 master pins?
@azz19:
The simple reason has been supplied above by MacGyver101...
The more technical answer has to do with the bitting system in use with the locks and the size of the bitting increment step (the amount of difference from one pin size to the next size)...
Many locks utilize what is called "two-step progression" in designing their keying systems -- like Schlage locks which use a .015" bitting step... Proper and valid keys designed in a master keying system will always be 2 increment depths apart in the same pin chamber of a lock... So you will have either odd or even depths in a given chamber... (0, 2, 4, 6 or
OR (1, 3, 5, 7 or 9)... Such locks need two increments between valid keys in order to prevent key interchange...
Other locks which use what is called a "single-step progression" in designing their keying systems -- like Kwikset locks which use a .023" bitting step... While you can use bittings one depth apart in a master keying system, it is not recommended to do so in every chamber of the lock because when the cylinder wears down over time you will experience unintended key interchange...
This can get confusing when you consider that some locks have different bitting systems that are used depending on which keyway you are using... Corbin-Russwin is noted for its plethora of bitting systems... "System 70" is single-step progression (.028" bitting step) and "Pre-System 70" is two-step progression (.014" bitting step)...
Now you can make locks work outside these guidelines, but you should not because you are intentionally creating something which will either not be reliable (it will eventually lose the pin between the plug and shell and could jam or cause a lock out as intended keys no longer operate) or would be unsafe when it becomes worn as it will allow unintended keys to operate...
~~ Evan
