Slitting the Nib
My entry point into the Sacred Circle of Nib Manufacturing
My time to enter into the nib making sanctuary arrived when they had slitting problems. The cutting blade manufacturer had replaced their ten year old product with a new version, had stopped production of the old, which had been slitting our nibs, reliably. The new discs did not. There had been a warning but who would have thought it would cause a problem. New is always synonymous with progress, with being better.
The slitting machine set at the previous speed caused the new disc to bent, wobble and finally shatter as soon as the tip of the nib touched it. The binding compound of the new discs had some lubricating agent in it which was good for stainless steel, they would last longer. But iridium needed the stiffness of the older discs. (see the chapter on materials)
The slitting machine operators were highly skilled; they positioned the nib and advanced the cutting disc manually. They would approach the iridium bead slowly and once the disc had scratched its surface, providing had a centring groove for the disc, then they would apply more pressure.
Once in the stainless steel they progressed more rapidly to the end stop of the slit or the hole. To centre each nib they used the bead, visually aligning it using a loupe with markings. They did not use any lubricant because they could not see otherwise.
I felt the solution lied in the field of being able to use lubrication. It was the time to build an automated machine where lubrication would not be a problem, much against the workers’ resistance. I promised not to tell anyone, it would all remain behind closed doors, as usual. But this time, I was inside.
My previous project had been in the ball pen tip production, where I had learned about lubrication. All secrets in ball pen production lays in the way lubrication is applied and what lubricant is used. Since I knew the right words and the technical sales bloke of a reputable lubrication manufacturer, I became the hero of the nib department. By now, we had run out of certain nib styles and sizes. Pressure was on.
The introduction of a numeric controlled advance system, (in house custom built after my design) and the right lubrication (from the ball pen department) solved the problem. And further, it also reduced the forming of burs thus the time of rumbling, the mechanised de‑burring process and occasional damage to the nib.
In the early eighties I started playing with cutting lasers and I worked fundamental knowledge for later introduction. The main problem was the heat control, because annealing colours appeared on steel and gold just melted away because of its high thermal conductivity.
During the eighties laser technology allowed lasers to be much smaller and focused tighter, less energy did the same job with less heat dissipation. Cutting lasers became economic to be introduced into the field of manufacturing. They needed no wearing tools and no burr was formed during the cutting.
But then again, without this problem occurring how else would I have entered into the nib manufacturing section?
Nib Manufacturing Process
The material for the nib, either gold or stainless steel, was often delivered in sheets or rolled up strips. In preparation for production the material was cut into about half metre long strips for ease of handling. The strip was feathered so it would stay straight during rolling.
The strips were passed through rollers, which left one edge of the strip at almost its original thickness, while the other edge was reduced down to about two thirds its thickness, sketch 1.
This work hardening would double or triple the hardness. The hardness of the thinner section would improve the stability of the nib, resulting in a firmer grip of the heel on the front part of the feeder and it would help the nib to set better in this section.
The gradual increase in thickness would cause the nib to have its characteristic elasticity and allow the opening of the slip under pressure in a particular, in the desired way.
Another reason for this reduction in cross section is the cost of gold. Rolling a gold strip in this fashion would reduce its weight by half (and half its cost) without any detriment to appearance or function. It actually approves function of the nib. Stainless steel nibs could have been produced flat but they have to fit on the same shape feeder and the production tools. Therefore they are produced in the same way.
After rolling the so called breather hole is punched into the strip, sketch 2. They were used as locating holes for the stamping out the flat shape of the nib and the subsequent forming, the placement of embossed imprints and for centring during the tipping process.
The shaping of the nib was completed by an initial polish to remove the burrs caused by the stamping process. After tipping and slitting the nib there was a second time of drum polishing; it was much shorter and the aggregate (small pieces of wood and shells of almond kernels) was softer.
The tipping process entails the welding of the tiny bead of iridium onto the tip of the nib. Three different size beads were used for the different widths.
Bead were welded on, using electric resistance welding under an inert gas atmosphere. Generally, electric resistance welding requires the materials of the components to be joined having a similar melting point and require a similar amount of energy to be brought to their melting points.
In case of nibs, this is not the case.
- the bead is tiny in comparison with the nib
- the melting point of osmiridium is around 2500 ºC
- gold’s melting point is around 1100 ºC
- stainless steel’s melting point is around 1430 ºC.
Non-matching parameter would vaporise one component before the other would melt.
Dilemmas such as this are part of an ingeneer’s life; you love it or change your profession. We did it and kept our success humbly quiet.
Shaping of Tip
During my fountain pen days, all nib tips were manually shaped to a certain width and angle. After the slitters, the tip shapers were second in the pecking order. Shaping was performed before the slitting, of course. Since I was a bit of a calligraphy buff, I learned how to shape tips.
Just a comment: In the sketches I left the tip round, spherical for ease of drawing.
About the slitting I have talked already extensively at the start of this chapter. I mention it here because of the completeness of the sequence.
The setting was another labour intensive, highly skilled process. It involved two actions. First, the slit needed to be closed again on the tip otherwise the ink would not move towards it. When the slit is cut with a diamond blade, sooner or later, the slit would get even wider towards the point due to uneven wear on the cutting blade. When this non-parallelity became too much (more than 0.2mm) the end of the utility of the blade had been reached.
The tines were brought together through impacting on their outer edge, the free side of the nib leave, photo 2. Through this impact the material would be elongated in this section. As a consequence, the slit would close at the tip. Often this impacting would happen on the underside or through embossing of ornaments.
At this stage of manufacturing, the ink would still stay in the slit and not cross over to the paper surface, unless pressure is applied to the nib and paper fibres are brought in contact with the ink. Therefore, even the nib production is completed, the fountain pens return to the final nib manipulation, after the nib has been slipped onto the feed, which by then has been inserted into the grip section.
In this second setting process the nib leave would be grabbed close to the bead with a small pair of flat pliers and the tine would be rotated inwards until a minute plastic deformation occurred causing a residual bent to achieve a permanent upside down “V” shape, when viewing the bead front on, sketch 3.
In the sketch I have emphasised the bending of the tines as well as the proportion of the opening. It is very minute, namely in the range from 0.15 to 0.25, also depending on the width of the nib. I just remember, this was the way, we did it 30 years ago. I am sure, today the process would be mechanised.
The final touch was given through de‑burring the edge of the gap in the bead with a knife blade shaped (oil free!) diamond polishing stone. I marked the area in red in sketch 3. The result was the smoothest writing you have ever experienced.
Through this shape, the lower section of the slit would always remain apart, which would be filled with ink. Through a gentle touch only, the fibres of the paper would enter into that gap and readily absorb the ink. I have described this in the chapter on Pressureless Writing.
All this setting was highly skill based and relied on trial and error and had to be tested continuously. Therefore, this happened all while ink was on the nib. What a messy business. You could not wear gloves, they would prevent the right feel, nor use barrier cream because if it would change the nibs performance, which would interfere with the setting procedure.
Setters had always blue fingers, it was a unspoken sign of their elite kudos.
In days of old, it would take about four months to break in a new nib through the wear caused by the owner’s personal writing style. I remember, when some serious writers would come to the factory to pick up their fountain pen and experienced setters would help them through this process in a few minutes.
The personalisation happened when the slightly shocked owner would be asked to write their signature about twenty times on 1000 grid polishing paper.
And… occasionally, a customer would ask about the people who make it all work. Those would have been some of the highlights of my working life, when I had the opportunity to meet a customer. Sometimes, they asked questions, and occasionally, I would give them a company tour.
This article on nib manufacturing is by far the most popular on this fountain pen design website. Hence, permit me a small amount of advertising on my own behalf:
At the moment, I am preparing an article on the feed, the component that makes a good fountain pen. You are invited to have a look over there: The Feed
In regards to nibs, continue to Nib Materials
Have you already read about the function of nibs? Nippy Nibs
14 September 2014