Fountain Pen Nib Size & Replacement Guide

Every fountain pen uses a nib to write with and it is made up of three parts which are the nib, ink feed, and the nib housing. When these three parts are assembled, they are fitted to the bottom end of the pen in what’s known as the nib section.

Many fountain pen nib units are manufacturer specific and cannot be interchanged with other manufacturers fountain pens. However, there are some nib manufacturers whose nibs are interchangeable with different makes of fountain pens. In this guide, we will cover all the main manufacturer’s nibs and nib sizes as well as how to replace the nibs.

1. Nib Manufacturers

In the early days, a lot of the fountain pen brands made their own nibs in house but today that is not the case. The two powerhouses in nib manufacturing are Japan and Germany. Other countries do make nibs such as France and India and it could be argued that China could be considered a powerhouse purely from a volume of manufactured nibs’ point of view.

1.1. Japanese Nib Manufacturers

Japanese Nib Manufacturers

The three main Japanese companies that manufacture nibs are Pilot, Platinum, and Sailor. Although there may are some smaller independent companies such as Nakaya whose craftsmen all previously worked for Platinum.

The Japanese nibs are made in house by each brand which makes them have different characteristics than other brands. It is worth noting that a Japanese medium & broad nib line width is roughly equivalent to a western nib. However, a fine and extra-fine are narrower by about one size. So, a Japanese fine nib line width is more closely related to a western extra fine and their extra-fine nib is a size down from that.

1.2. German Nib Manufacturers

This is where nib manufacturing starts to get interesting like Japan there are German pen brands that make their own fountain pen nibs in house such as Lamy and Pelikan. However, there are two main specialist nib manufacturers who produce nibs that are a standardized size that is used by many different pen brands. Although they also produce custom sizes as well.

Jowo and Bock Nibs Logos

These are Bock and Jowo and are usually known as #5 and #6 nibs. Bock uses a three-digit code to denote size. 250 is their standard size which is equivalent to a Jowo #6 and 180 is their standard size which is equivalent to a Jowo #5. Generally speaking, it is possible if the fountain pen has a friction fit nib then you can swap #5 nibs with other #5 nibs and #6 nibs with other #6 nibs. However, you cannot swap a #5 nib with a #6 nib or vice versa as a #5 nib and feed is a lot slimmer and shorter than a #6 nib.

There is one caveat here “generally speaking” there are some nibs that cannot be swapped even if they are both a #5 or a #6. You can permanently damage your fountain pen if you get it wrong our advice would be to do an internet search for how to swap the nib on your brand and model of pen. Then search a forum such as The Fountain Pen Network. If you cannot find the answer, then ask a question on the Fountain Pen Network and somebody will be able to help you. Alternatively, you can ask a question on the fountain pen sub edit r/fountainpens.

Speaking of Reddit there is a very good subreddit on swapping Jowo #6 nibs that is well worth taking a look at.

2. Chinese Nibs

Chinese No 5 and No 6 Nib Comparison

The fun really starts when it comes to Chinese fountain pen nibs it is a minefield trying to determine who the manufacturer of a nib on most Chinese fountain pens really is. When you throw into the mix that when some German nib manufacturers went out of business their equipment was bought up by Asian companies. So, you will find some Chinese nibs stamped with Iridium point Germany as they have not changed the dies and lets face it it’s not bad from a marketing point of view even though the nib has never seen Germany in its life.

On the plus side #5 nibs are quite common on Chinese pens and usually can be swapped out for a different no 5 nib. However, you will need to do some research first before trying to swap a nib as not every #5 nib will work in every #5 nib pen.

An example of this is a Delike fountain pen nib uses a number 5 nib but the nib is shorter and slimmer so the feed would not work properly if you swapped out the nib. Another example is the Wing Sung 659 & 698 can take a number 5 nib but it is Pilot style nib and feed, so it is not compatible with Bock & Jowo #5 Nibs.

There are also some Chinese pens that take a #6 nib The Jinaho X750 is a very popular inexpensive Chinese fountain pen with a #6 nib. This is often swapped for a German Bock or Jowo replacement nib. Also, a lot of people swap the nib for a Japanese Zebra G Super Flex steel nib which is also a #6 nib and only costs a few dollars.

3. Replacing a Fountain Pen Nib

So how do you replace a fountain pen nib and fit something different to it. Before you go diving in a quick disclaimer removing a fountain pen nib can permanently damage your nib and pen. If you choose to do so it as at your own risk and I cannot be held responsible.

My advice would be to practice on cheaper Chinese fountain pens first and if in any doubt don’t try it out on more expensive pens. Now that’s out of the way nearly all fountain pen nibs can be removed and replaced.

It may be a few years old but Kevin over at Fountain Pen Revolution does a good job of showing how to replace a nib and feed in this video.

3.1. Friction Nibs

You may have already seen people on YouTube simply pulling the nib and feed out of the end of the pen. These are what’s known as friction fit and the best type for swapping your own nib but there are other types that we will go into more detail.

Things to bear in mind is when replacing friction fit nib and feed is that the nib housing may have a small locating groove cut into it so you will need to make sure that the feed is sat in the center of the nib and orientated correctly so that its locating lug will fit in the locating groove of the feed.

It sounds complicated but isn’t too bad when you have the nib and feed out of the nib housing. Hold the nib housing up to the light and you will see if there is a locating groove cut into the wall of the housing.

3.2. Threaded Nibs

Some fountain pens such as Kaweco have a nib and feed that it is pre-assembled in a housing with a threaded end that screws into the barrel. With these types of pens, it is best to swap the complete nib unit as you may not be able to take it further apart without damaging it.

Photo of author

Peter Warrior: Pen & Pencil Expert

With nearly a decade of experience in the pen industry, I successfully ran an online pen business for 9 years. My deep-rooted passion for pens and pencils led me to become a part-time blogger, where I've dedicated myself to sharing the wealth of knowledge I've amassed over the years. I'm a firm believer in the power of the written word, as echoed by Malcolm Forbes: "Putting pen to paper lights more fire than matches ever will." My expertise is not just rooted in business, but in the genuine appreciation and understanding of the art of writing instruments.

3 thoughts on “Fountain Pen Nib Size & Replacement Guide”

  1. Can I find a replacement nib for my Peneider Arco Blue Bee with a 14 ct. quill nib. It’s a medium and is far too wet for my writing style. Does Bock make their nibs? Need a fine or extra fine. Would prefer a ebony feed.


    • Hi, Dave sorry I don’t know the answer to this the best place to find out would be to post a question on the Fountain Pen Network Forum.


Leave a Comment