I want to replace the external strip which retains the driver pins with grub screws.
I'm going to list the specs I've chosen so others may duplicate or improve upon it:
An M3.5 thread seems like the best fit for standard pin sizes (2.8mm / 0.115") - the specs are almost identical to 6-40UNF which has been previously recommended on this board, but suitable taps and screws seem more readily available.
The minor diameter is 2.78mm which is slightly smaller than standard pin sizes
The major diameter is 3.5mm giving >0.3mm thread width to support each side, but without encroaching on neighbouring chambers.
An M4 thread will be a better fit on a used lock where the chambers have been worn provided the pins are spaced far enough apart.
I've posted elsewhere that worn chambers in a used lock can often take 3.1mm pins - the minor diameter of M4 threads is 3.141mm, so they should fit once the tap has bored the chamber.
The major diameter is 4mm, giving 0.43mm support on each side.
My question is how long the screws should be?
M3.5 has a 0.6mm pitch, so a 4mm long screw would have 6.7 turns supporting it.
Is that enough?
Would anyone with practice locks using grub screws be able to measure them?
Grub screws:
https://tinyurl.com/vn27tbf
