Fountain Pens: Whither Iridium?

For more than a hundred years, the very tips of the nibs on most good-quality fountain pens have been made of, rather than steel or gold, as the rest of the nib, a very hard chunk of metal usually referred to as iridium.

Iridium itself is a fairly rare element of the platinum family, and it’s widely known that the “iridium” tipping on modern fountain pens contains no actual… iridium. Fountain pen geeks with scientific backgrounds have actually run tests, and found that there hasn’t been any actual iridium in pen points since, probably, before WWII.

On his website, famed “nibmeister” John Mottishaw has a couple of articles about this, the most pertinent of which is right here. In it, he asserts a couple of things about the tipping of early fountain pen nibs, most notably that they were made from crude pieces of unrefined ore.

Elsewhere, he points out the rough, porous nature of some early pen tipping – easily seen under a high-powered loupe – as having been caused by corrosion – further proof, he thinks, that early pen-makers were using unrefined material they were not “in full control of”, as you somewhat obviously wouldn’t choose to make a nib of something that would be attacked by ink, right?

I know it takes enormous hubris to suggest that a man of Mr. Mottishaw’s stature could be wrong, but I’d like to direct your – and his – attention to the March 3rd, 1883 issue of “Mechanics”, the “weekly journal of engineering and mechanical progress”.

In the link above, John Mottishaw seems to question whether iridium was in fact ever used as a pen point in and of itself, rather than as an alloy. (Footnote 3: “Kurt Montgomery pointed this reference out to me. He said, “This is an interesting reference since it is contemporary with some of the nibs analyzed. In the 1941chapter on iridium, there is no mention of using pure iridium as a pen tipping material, either currently or previously.”)

In 1883:

“This… brings us to within a few months of present time. At this stage of the subject I have the pleasure of presenting to you results of the labors of Mr John Holland, the well known gold pen manufacturer our city. Mr Holland being engaged in manufacture of what are known as diamond pointed pens, the points being in fact iridium, it was quite natural that he should be impressed with the desirability of some means of better preparing the metal to meet his own wants in his branch of manufacture. About 18 years ago he commenced his experiments to that end and never ceased his efforts sparing neither time money in his determined pursuit of the object. At last his labors have been with complete success. He placed a quantity of the metal in a Hessian crucible and after raising it to a high heat he added a stick of phosphorus, when to his delight as soon as the fumes away he saw the liquid mass of metal the bottom. It was at this stage of the discovery that the author of this paper acquainted with it. For certain purposes for which it was proposed to use the metal it was found necessary to remove the phosphorus which it contained and this was the first problem that demanded attention. After various experiments it was found that lime was best adapted to the purpose. The metal after being melted and cast into shape is embedded in lime contained in a Hessian crucible, and subjected to a high heat. This process is repeated several times, each time allowing the metal to remain in the furnace longer than before, when after four or five such operations phosphorus is practically all removed, combined with the lime. For the want of better name and since the metal is rendered much tougher we have termed this the annealing or dephosphorizing process. The removal of the phosphorus renders the metal slightly porous but it is as refractory as the original.”

Skipping ahead a bit:

“On casting we sometimes find the metal slightly porous. The polished surface to the naked eye may look perfectly homogeneous, but under the magnifying glass minute holes may be seen. In order to obtain the iridium in a convenient form for making pen points the molten metal is poured upon an iron plate. when the workman immediately strikes it with a heavy iron thereby flattening it out into a slab of about 1/32d inch in thickness. This slab is broken into small pieces which are then ground into the proper shape.”

“One ounce of iridium from 5000 to 10,000 pen points. The iridium melted by this process is compact and crystalline; it is harder than the natural metal.”

It seems that what we think we know of the history of pen tipping needs to be revised somewhat; pen makers as early as the 1880s were not reliant upon raw chunks of natural iridium ore to tip pen nibs with, but were manufacturing their own somewhat refined material – one whose manufacturing process created some telltale signs (porosity) which are frequently visible in the tipping of fountain pens a half-century later.

To be sure, some iridium alloys were made, accidentally or otherwise – the article linked to above described several types of alloys “studied and known to possess many interesting and valuable characteristics” – but the use of “unrefined ore” as a raw tipping material, as Mottishaw puts it, was already outdated by 1900, let alone WWI, the era of the oldest nib whose composition he examined.

Published in: Geekiness, General, History | on May 11th, 2011| No Comments »

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