Needle screw Alan key type,fit jack overlock industrial machine

Needle screw Alan key type, fit jack  overlock industrial machine 

This needle screw is a direct replacement for your industrial overlocker. 
This screw is used to hold in place the needles and is to be used in conjunction with the correct sized Allen key (provided with your machine)
The  Overlocker Needle Screw can go missing if you unscrew the blighter all the way. 
Remember, when you're changing your needles you only need to unscrew the screw one revolution, or so. 
This is the type which requires an Allen key to unscrew and tighten.