If you can not screw the nib section out, please send us a message, we will send you the replacement part to fix this. Asvine Pen Replacement Asvine German Bock #6 Fountain Pen Nib - Blue Extra Fine Point With O-Rings For Piston Fill Pens Extra Fine Nib 3 Pcs Asvne Fountan Pen Replaced Nbs, 6 Extra Fne, Fne and Medum... Please remove the cartridge or converter before twising the nib out. 1., Easy to replace the nib by twisting it out and back. New Pen Day Asvine P36. (Asvine F Nib) : r/fountainpens These nibs are not standard size, they are compatible with any fountain pens which work with #6 Bock nib unit like Asvine P36, P50, P80, and V200., If your pens are not piston or vacuum filling, please remove the gasket from the nib unit before replacing., EF F M Nibs Asvine P50 Piston Acrylic Fountain Pen EF/F/M Nib Smooth Writing Office Gift Pen Fountain Pen Nib Unit Package: 3 pcs nibs with black section