Nib Threads

Vintage Eversharp
.225″ Ø   –   48 tpi
bore thread hole .210″ Ø about .75″ deep, relief to .282″ Ø about .485″ deep
thread the 48 tpi .720″ deep

 

Vintage Morriset
threads are .347 Ø   –   36 tpi
drill hole .625″ deep with .250″ Ø or so bit
bore .520″ deep to .332″ Ø
bore .100″ deep to .358″ Ø
thread 36 tpi .363″ deep, to .360″ Ø