Two days after I purchased it, I dropped my Pilot Metropolitan NIB straight down onto a hard floor.
Rather than keep the pens as parts, I chose to try a cheap Chinese nib. The NIB is listed as EF and 0.38mm. I believe that the Pilot F nib is 0.32mm, so, this is pretty close, but larger than, the Pilot Fine nib.
The nib is gold in color and it reads EF/CLASS/YONGSHEMG I think.
I am attaching sample writing using the Chinese EF nib with a pen loaded with a Pilot Blue Cartridge. The black writing is using a Pilot F nib.
I purchased three nibs for about $5 on eBay from assassin813. I was then asked which nib I wanted, F or EF. At the time I did not know that the EF was closer to the Pilot F, so I am glad that I chose the EF over the F (.5 mm).
It seems to be writing well right now, but the Pilot nib is smoother I think. The Pilot nib was awesome the moment I inked it up, I had to write a bit before the Chinese nib started writing better.
AT the end of the day, I am pleasantly surprised at how well this cheap nib performs, but, only time will tell how well it continue to performs.
Close up of the NIB:
Nib on the pen:
Text written with the Chinese EF nib:
Comparison with the Pilot Fine Nib (Black) and the Chinese EF nib (blue). :