The Shape Of The Hole

[AAAndrew]

Most holes in nibs are fairly boring. But every once in a while, back in the days of the steel dip pen, when manufacturers offered thousands of styles, the hole in the nib would take a different shape.

 

I just bought myself a light board and decided to see if I could show a few interesting examples I had lying about.

 

From left: Esterbrook 914 bank pen, Hunt 709 Courier Stub, Hunt 1681 Pennsylvania (Pennsylvania is known as the Keystone state hence the hole in the shape of a keystone), Spencerian 41 Panama Pen (originally made by Perry).

 

[Bo Bo Olson]

Interesting.....Andrew do you think many were just made as 'brand name' marks or did some seem to have a purpose?

[AAAndrew]

Steel nibs all had piercings, though, as far as I have been able to figure out, they really only serve one purpose, it reduces the amount of steel at the top of the slit to increase flexibility. The larger the opening, the more impact it has, though the impact is always tempered by the thickness of the nib.

 

Many pens with unusual hole shapes seem to have no relationship to the pen brand or style name (Panama and ax?). The Keystone pen is one of the few I've seen with some kind of relationship with the style name.

 

Some, like Bank Pens, and Manifold Pens have hole shapes that are standard across manufacturers. All Bank Pens have that torch-shaped hole, and all Manifolds have a round hole.

 

I think I need to do a study.

[bobje]

The ax is wild, and torch is lovely. Sounds like they hadn’t yet thought through branding opportunities.

[Astronymus]

It also reduces the stress at the point where the slit begins.

[AAAndrew]

It also reduces the stress at the point where the slit begins.

This is a commonly quoted reason. I see this as possibly more true with gold than steel, but would love to actually test this someday. It may have been true early on with more brittle steel, but my experience with hundreds of different styles of steel pens is that if one were to put enough pressure on the tines to possibly split the steel at the top of the slit, youd ruin the pen first.

 

My theory is that it may have been necessary very early because of steel quality, but as steel greatly improved by the 1840s, it wasnt really necessary but was now traditional.

 

Look at the brass pens like the 314 Relief by Esterbrook. Brass is much easier to cut through shearing action, yet that pen doesnt have a hole. Same wih gold, and some gold pens have a hole but many dont.

 

There are a lot of stories told to explain the hole, it helps hold more ink, it helps prevent spitting, but none of them hold up under scrutiny.

 

Id point to one example of a hole that, in my mind, if it was here to prevent the splitting of the pen at the end of the slit, would actually make it worse.. this is the typical piercing for the long, thin, spear shape pens. The piercing is long and thin, effectively lengthening the slit further down the pen. And many of these shaped pens are pretty flexible with an easy spread and thin steel. Yet theyre not know for cracking at the end of the piercing. The one Im talking about is on the left. It is by Blanzy Poure, who made a number of styles with his same shape in various levels of flexibility.

 

That is not to say the piercing at the end of the slit has no purpose. The real purpose is to reduce the amount of material in he middle of the pen, at the top of the tines, to help with flexibility and center softness of the pen. In most cases I dont think the impact is very great, but I suspect the action of the pen would be worse without it.

Edited March 10, 2019 by AAAndrew

[steve50]

Could someone shed light on the purpose of two breather holes on some vintage German nibs? My guess is that the bottom one was already there, and they didn't cut the slit all the way down so the nibs are stiffer. And they added another breather hole where they stopped. Am I correct?

Edited March 10, 2019 by steve50

[Carrau]

The nib on the far left reminded me of the opening seen on many double edge razor blades. Ive often wondered what the purpose was on the blades, and now I wonder if that had to do with flexibility as well.

[AAAndrew]

I’m no expert on fountain pen design, but to me the lower hole, not connected to the slit, is a true breather hole, to allow air to enter and balance air pressure, while the smaller one at the end of the slit is for the purpose mentioned above, to support the end of the slit.

[AAAndrew]

The nib on the far left reminded me of the opening seen on many double edge razor blades. Ive often wondered what the purpose was on the blades, and now I wonder if that had to do with flexibility as well.

These blades did bend in the middle to form a curve once placed in the razor. I have an old razor that uses these but have used it in a loooong time. Not sure why the shape is so filled with curves and protrusions.

[steve50]

I’m no expert on fountain pen design, but to me the lower hole, not connected to the slit, is a true breather hole, to allow air to enter and balance air pressure, while the smaller one at the end of the slit is for the purpose mentioned above, to support the end of the slit.

Is that 'breathing' function really what the holes are for? I was told that it's actually a misunderstanding that the hole is necessary for air to travel. I was thinking that the holes were introduced on dip nibs, which obviously do not need air travel, etc., for some other reason, and they carried on with fountain pen nibs.

[Carrau]

I sent an email to Amadeus W., whose website Fountain Pen Design, is a marvel explaining the engineering behind nibs/feeds, etc. With luck, he’ll find a bit of time to respond and maybe shed some light on this on this interesting topic.

[Astronymus]

This is a commonly quoted reason. I see this as possibly more true with gold than steel, but would love to actually test this someday. It may have been true early on with more brittle steel, but my experience with hundreds of different styles of steel pens is that if one were to put enough pressure on the tines to possibly split the steel at the top of the slit, youd ruin the pen first.

 

My theory is that it may have been necessary very early because of steel quality, but as steel greatly improved by the 1840s, it wasnt really necessary but was now traditional.

 

Look at the brass pens like the 314 Relief by Esterbrook. Brass is much easier to cut through shearing action, yet that pen doesnt have a hole. Same wih gold, and some gold pens have a hole but many dont.

Indeed. It also depends one the yield point of the certain material. And the overall construction of course.

But it does reduce stress at the base of the slit as a fact. Had to change the slits on a spring plate construction myself because the lamellar blades would break of all the time. At exact the same point at the base of the slit. Sharp edges will focus force and lead to growing fissures. Same happened to the first jetliner, the De Havilland DH.106 Comet. I think five flights were lost.

We have seen in Lamy-Video here how the ends of the slits on the steel Z50 nibs are hardened by laser. On some nibs you can see one or two circles on the underside. Yet the gold nibs don't have a hole at all.

Is it always neccessary on nibs? I guess we would have to ask the each manufacterer.

[wallylynn]

I find it interesting that my noodlers flex nibs do *not* have the hole.

[Carrau]

Amadeus responded to my email, referring me to a section of his website entitled Flex Nib Modifications (see link). If I understand his discussion correctly, it seems on dip nibs breather holes improve the ability to hold ink through the magic of capillarity/surface tension (steve50 pointed this out in his post), and it would seem that at a certain size, the capillarity/surface tension may become great enough to impede flow, so there’s is probably an ideal range of size for the hole in dip nibs. Apparently the shape itself does not affect ink flow, however, as Astron also points out, sharp corners can “cause high stress points and subsequent fatigue cracking.” The size of the hole can affect flexibility, depending on how it affects the breadth of the nib with a given radius of curvature of the nib. Whether a breather hole is necessary apparently depends on the design of the feed and whether the the air canal is in the top or bottom of the feed. If you wish more detail, the link follows.

https://fountainpendesign.wordpress.com/fountain-pen-nib/flex-nibs-experience/flex-nib-modification/

[Taverius]

You would indeed break the pen before you could crack a hole-less nib at once, but that's not he mechanical reason its there - but to prevent stress cracking from fatigue over years of use.

 

Is it necessary?

 

Depends on the design of the nib and the temper of the metal - and the alloy itself, in particular some gold alloys are slightly work-hardening and even more prone than steel to fatigue damage.

 

When I make outdoor/survival knives I relieve stresses on concave bends that way, on kitchen knives there is no point, because of how they're tempered and designed.

 

Likewise with nibs.

 

Do note, something like 90% of the stress tipically is in the 180-240° arc facing opposite the tip, so extending the rest into a keyhole or other shape doesn't really affect it much for most nibs.

 

Furthermore, that is only for the classic nibs shape. Side cutouts, like are common with modern flex, as well as more complex geometries like a Pilot Falcon can have very different mechanical stress distribution, such that in some cases the slit is not a stress focus at all.

[Carrau]

All discussed and demonstrated on Amadeus’ website.

[BaronWulfraed]

I find it interesting that my noodlers flex nibs do *not* have the hole.

From the ones I own, that may be because the slit is cut all the way up to, and even into, the section. That far up, the section would prevent splitting further.

 

Presuming the hole is not truly meant for stress relief -- I'd nominate that it is to provide a "stop" when cutting the slit. The hole can be stamped or drilled using a fixture holding the nib, so a repeatable location -- but slits were cut by hand, so having the hole meant the slits are the same length nib to nib.

[AAAndrew]

A few things.

 

1. I don't accept the argument that the hole has anything to do with ink and capillary action on dip nibs. This argument is never made contemporary to the time when dip pens were actually used. I can only find it from recent times when people look at dip pens through the lens of knowing about fountain pens. For example, this is when people start calling it a breather hole. In real-life use, most of the time my ink does not completely cover the hole at all, and so the hole has little to nothing to do with the storage or flow of ink. Plus, the way ink is held under the nib, a solid surface holds more ink than a piercing. When the ink does cover a piercing, it thins to a transparent "window" but when it's on the solid part a much thicker layer of ink is held. Here's a picture of a typical dip.

 

 

As someone who has used hundreds of types and uses them every day, that argument does not align with experience.

 

2. The central piercing may prevent stress fractures from happening over time, but steel pens are disposable and may last a month of regular use, if that. Again, it sounds like a post facto justification. Gold pens are more likely to be used for a long period of time as they don't corrode. Brass pens also don't corrode and last a bit longer than steel pens, yet they don't have a central piercing.

 

3. The piercings are one of the first steps in making a pen while the slit (not cut by hand since the 1820's discovered the screw press to cut them) is one of the last steps before final polishing. So, the piercing is not needed for making the slit. The tip is much more important for aligning and cutting the slit than the central piercing.

 

So, I'm still looking for a real, functional reason for a central piercing that stands up to actual experience.

Edited March 11, 2019 by AAAndrew

[AAAndrew]

I went back to one of the sources, namely Henry Bore's, The Story of the Invention and Manufacture of Steel Pens from 1890. In his description of the steps to make a steel pen, he includes "Piercing." In that section he calls it the "Centre Pierce" which I've since found out, "pierce" is a standard term in metal working for such a hole. Bore mentions that it is often decorative. He also lists it as one of the ways of introducing flexibility into the pen. And in this instance, I would read "flexibility" as the broader term that includes softness as well as spread of tines. He doesn't say anything about relieving stress on the end of the slit, or capillary action.

 

So, "Center Pierce" is what I shall call it, thus staying true to the craft terminology as well as an early authority.