4.4 Nib Materials

Gold

Gold’s most astonishing characteristic is its malleability.  In its pure as well as low alloyed forms it does not work-harden, meaning, plastic deformation does not make it harder, a characteristic most iron-based alloys possess. In the (g)olden days, this feature, that it wouldn’t work-harden,    for any practical use, except jewellery. Since gold didn’t corrode, it had been the preferred choice material for nibs (ink was even more corrosive than today), however, early gold nibs would bend very easily and possessed hardly any elasticity, moreover, writing would wear them out quickly. Hardened steel nibs presented superior qualities but rusted away in days; quills lasted much longer.

Since 1848, a New York company named A. Morton & Co. made gold nibs amongst other writing items. They must have known a trick because German fountain pen manufacturers imported them since 1883. I assume that they used already alloyed gold including materials such as silver, copper, and nickel to achieve higher mechanical stability, hardness, elasticity, tensile strength and not to forget: it would work-harden.  As a result, gold alloys were able to fulfil the task of writing and became useful for the production of nibs. I will talk and explain details in the chapter Stresses and Strains.  A side-effect of alloying can be a noticeable change in colour.

Standard 14-carat or 585 (just another way of saying the same) gold contains 14 parts of gold, 8¼ silver and 1¾ copper (should add up to 24 carats altogether). In the alloy for fountain pens, the amount of copper is increased to 3¼, silver is replaced by 5 parts of nickel and 2 parts of zinc. Nickel improves hardness significantly. Vickers (the name of the guy who established the measuring method) hardness of pure gold is about 30MPa (Mega Pascal), that of 14-karat fountain pen gold is up to 200MPa. And further to this, the nickel-gold alloy work hardens. A significant, essential characteristic of nib manufacturing.

Mega Pascal?  Blaise Pascal was a French mathematician,  physicist, inventor, writer and Catholic theologian, all this during his short life of 39 years in the sixteen hundreds!  Today, it’s the unit of measure for pressure, just like psi for tire pressure.  The passenger car tire pressure of about 32psi converts to 220kPa or 0.22MPa.  Before that, ingeneers had to work with N/m² (MPa = N/mm²) and before that kg/m · s² and before that with bar and kp/m².  (I completed my degree in 1970.) Why is that so?  The physics haven’t changed?  There are some ingeneers sitting in committees around the world who justify their existence by deciding on in what new unit of measure the same thing must be expressed from now on.  The stubbornness amongst those involved increases, and so does the muddle up, over-proportionally.

Nevertheless, from experience, I can say: gold nibs are much more prone to damage through being bent when applying excessive pressure during writing. It is also common knowledge amongst fountain pen users that gold nibs, generally speaking, respond more readily to increased writing pressure by widening the line.

Some writers like this attribute and choose a gold nib because it gives their writing more character. I mentioned this fact already in the chapter about the nib’s function.

Stainless Steel

Stainless steel as it is in use today was introduced between 1913 and 1935.

The type of stainless steel for producing nibs is called austenitic steel, one which has attained a crystalline structure (of the austenite). How this happens? The iron alloy is heated to a particular temperature (727 °C) when it assembles the austenitic structure.  Then it is quenched quickly so that the alloy molecules remain in this structure; the presence of nickel stabilises this structure.  Other alloy additives would result in different qualities, such as elasticity, malleability, or ease of machining.

The stainless steel alloy for nib production is a low carbon steel with increased weldability, which is critical for the nib’s tipping process.  In addition, it is non-magnetic (not that important).  The ability to work harden this material is its most significant quality. During this process, its yield strength,  which is essential for the elasticity (see Material Technology) increases from somewhere around 240MPa to 760MPa. The hardening comes for free because during manufacture when the steel is cold rolled into the particular cross-section.

Annealed (soft and free of stress through heat treatment) stainless steel of this type has a Rockwell C (another way of measuring it) hardness of 10 and can be work-hardened up to 32. This is less important for the writer but significant for the manufacturer.

In the EN-standards (European Norm), the name of this steel X2CrNiMo18-14-3 where X2 stands for low carbon steel and is very similar to the well known 18/8 chromium-nickel steel.  It contains about 65% iron with its major components being C(h)rome 18 – Nickel 14 and Molybdenum 3.  But wait, there are a few more: C Si Mn P S Cr Ni Mo Ti Cu and above all and not to forget: Miscellaneous (who knows what that is?).  Besides the major ones, all other components are present in ppm (parts per million), which gives you an insight into the alchemy of the real world.

Both ASTM (American Society for Testing and Materials) and AISI (Australian Industrial Systems Institute) name this type of stainless steel 316L. The German DIN (Deutsche Industrie Norm) calls it 1.4436.

Osmiridium / Wolfram

Whether made of gold or stainless steel, each one of the nibs in the company I worked for had an iridium bead of 1mm diameter welded on its tip to reduce nib wear through writing as well as the friction between the nib and the paper. Casually, we call it iridium, but actually, its proper name is osm-iridium.  In nature, osmiridium occurs as an alloy, containing 30 – 60% of the platinum group metal Osmium.  The blend with platinum makes it much easier to process, to weld it to the nib-tip.

In the company I worked for, we used the hardest metal on Earth, it is called Wolfram, the same as Tungsten (the pure element with the symbol W and atomic number 74) with tungsten-carbide (link to THOMAS website) being its most common alloy.  I collected four comparative properties in table 1:

Table 1
	Tungsten/ Wolfram	Osmiridium	Stainless Steel 316L	Gold 14k
Specific gravity [g/cm3]	19.27	22.65	8	12.8
melting point  [°C]	3410	2450	2500	855
Tensile strength [MPa]	1725	2000	515	467
Rockwell C hardness	89+	56	20-39	around 8

Note that the melting points of osmiridium and stainless are almost the same, which is the reason why fountain pen manufacturers tend to prefer it to tungsten because these two metals are much easier to fuse.  Furthermore, there is tradition:  At the time of early nib construction, osmiridium had been by far the hardest metal available, it can be found in nature. It was also used as pivots in instruments and clocks. Fountain pen makers, like all artisans, are traditionalists, and they stick to what they know. Today, forty years after my fountain pen time, there may be something better around.

The table tells you, that fountain pens from a reliable manufacturer are designed for extended periods of usability. Iridium is at least ten times harder than gold, thus, one could condescendingly discredit today a gold nib without a hard metal nib as “practically useless”.  But how many replace their mobile phones even it still works when, after one year, the next model appears?  Let’s have a closer look at this statement. If a bare steel nib would last for 20 years — if written for hours every day — and an osmiridium tip for 40 or a tungsten tip for 80, how far into the future do we need to go to justify the effort?  Most probably, it’s users’ expectation (even quite irrational) that dictates this part of nib production.

Better pens use 14k solid gold points, while lesser ones use steel.

A common misnomer.

Let me rephrase this statement: More expensive fountain pens often come with gold nibs. This gives them a higher perceived value, people are prepared to pay over-proportionally much more. The cost of gold nibs is about ten times higher than stainless-steel nibs; apply this bit of knowledge in your next fountain pen appraisal.

The internet told me that by far, most fountain pens at an average price (over $100) are equipped with steel nibs. If the famous 585 is not on the nib, it is gold-plated through anodising (electrochemical) or fused with a rolled-on thin gold layer, mainly only on the top side.

More crucial for a nib’s reliability (if this means better) is, whether it has been constructed properly and been tipped with an iridium bead because that is what makes them last.

People say: “Gold nibs write smoother” or “they have more character”. Translated into technical terms, this could mean: the line width alters more readily due to a change in pressure. Is that of importance? The same can be achieved by a steel nib.  If in doubt, visit the next chapter about 051-2-1 Stresses and Strains.  Anyone who calls himself a good nib maker can construct one to make it suit this purpose.

Concluding, I would like to boldly add one statement: after you have read the entire article on nibs, you know more about them than some nib makers. The big number of unsatisfactory nibs in the market is sufficient proof of this statement.  I can say this after inspection of many nibs, including those, which are attached to some very expensive fountain pens. If they were aware of this lack, I am sure they could make a better nib.

A better, good, well-designed nib does not cost a cent more than a shabby one, it needs more knowledge and care by the ingeneer and maker.

Above all: Enjoy!

Ω

Amadeus W.
Ingeneer

14 September 2014

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