JoWo Nibs

To know which JoWo nib fits your pen, first confirm whether it takes a #5 or a #6 unit. #5 nibs are built for 5mm feeds and #6 nibs are built for 6mm feeds, with #6 being the industry standard and #5 mostly found in compact and pocket pens. You’ll find the most reliable information from your pen maker's nib specification. Fitment also depends on how the unit sits inside the pen and whether it’s a screw-in or friction-fit, which varies from pen to pen. If yours isn’t built around a JoWo unit at all, the broader fountain pen replacement nibs collection covers other makers' fitments.

They’re often interchangeable between pens built around a #6 unit, but it’s not a guarantee. Some makers use brand-specific housings with non-standard threading, and some aftermarket makers design custom housings, so it’s possible for a nib to look like it will fit, but it doesn’t. Same-size swaps within one brand are the safest bet, but if you’re doing a cross-brand swap, check the pen maker’s specs first so you don’t end up with an expensive desk ornament.

Yes, and they’re backed by JoWo's reputation as one of the leading German OEM steel-nib makers, alongside Bock and Schmidt. It’s the factory-standard nib for major brands like Esterbrook, Leonardo, Edison Pen Co, and Diplomat.

The JoWo nib is often described as firmer, wetter, and less pliable than a Bock nib, which typically writes a little wider and has a springier metal. Both are German-made and closely matched on quality, so the choice comes down to whether you want a nib that’s smooth and consistent or springy and tactile.

A JoWo nib generally writes smoothly straight out of the box, since the tips are ground to a consistent standard. Because the feed in your replacement nib might not supply ink at the exact same rate as the original feed, a swapped nib occasionally needs light tuning or alignment to deliver its best ink flow. Flex and stub units are most sensitive to this, since they lay down more ink on paper than other nibs and therefore rely on a steady flow.

To make sure you’re getting a genuine JoWo nib, place your order with an established specialty pen retailer rather than a third-party marketplace seller. JoWo supplies its nibs to other reputable pen brands like Esterbrook and Conklin, so genuine units are often unbranded or are stamped with the pen brand’s logo. This means you can’t confirm authenticity based on markings alone, and a listing that says "JoWo-compatible" is not proof of a true JoWo unit. As a specialty retailer and authorized dealer of the pen brands we carry, we can assure you you’re getting the real deal.

Replacement nibs come in two sizes, #5 and #6, and various tip widths depending on nib size. Flex units are stocked here, too, for writers who want line variation. Every nib in this collection is stainless steel, with color options in black, gold, rose-gold, and silver.

A JoWo flex nib, available here for the #6 nib size, writes with elastic tines that create a noticeably broader stroke when you bear down. It allows for line variation but has a more responsive spring than the “wet-noodle” flex of vintage nibs. A flex unit writes best with a wet, free-flowing ink that can keep pace with the feed and avoid railroading. Nobody wants a faded line!

To install a replacement JoWo nib, first match the size (#5 or #6) to what your pen requires, then unscrew the grip section and remove the converter or cartridge. Unscrew the old nib unit (nib, feed, and housing) and thread the new unit in by hand. Work gently and keep the nib and feed aligned, since forcing a unit is the most common way a nib gets damaged during a swap.