Functional lock picks with robustified hook design.

1mm or 0.7 mm hook thickness

Print with 5 walls/100% infill

Use stiffer materials such as PLA, PLA-CF. 

ABS or PETG are more flexible which is bad for printed lock picks.

Check out Lock Pick Tensioners and Notch Decoder too:

https://www.printables.com/model/1103439-lock-pick-tensioner

https://www.printables.com/model/1105728-lock-notch-decoder