Singer 221g hardware question

[Agent319]

I have a 211W155 and a 211G156 and I have the exploded parts view diagram of these machines.  In the diagram the screw parts listed have either a -803, 804, 805, 806, 819, 830, 833, 850 or 819 after the part # and many of those -#'s are the same.  Would anyone know what those dash #'s represent?

[ksteers]

following

[Agent319]

I came across this https://www.singersewinginfo.co.uk/screw_threads

"Because Singer factories manufactured all of their own components it was not as important for them to ensure standardization of items from different suppliers. Although many older Singer threads matched those of the American and then Unified standards, they continued to use some sizes that were non-standard in order to maintain backward compatibility between parts that were common to different models."

 

Those -#'s after a screw part # is Singer tap/die# used to cut the threads for a screw or a hole.

 

 

 

 

[Wizcrafts]

1 hour ago, Agent319 said:

Those -#'s after a screw part # is Singer tap/die# used to cut the threads for a screw or a hole.

That's good to know! @CowboyBob has sets of actual Singer taps and dies that he uses to repair old Singer sewing machines in his shop: Toledo Industrial Sewing Machines.