0.5mm Pencil Lead

[SlideRules]

My favorite lead size was always 0.5mm and for many years I wouldn’t even consider using a different size. I didn’t even know about the smaller lead sizes until decades after using 0.5mm. I know other people had similar feelings for 0.7mm and 0.9mm sizes. (I didn’t know it at the time, but my artist friend used/uses a PMG for some of his artwork.)

I have only just done a tiny bit of research, and I don’t trust AI based on the inaccuracies I’ve seen for some of my other searches, so thought I would ask here. Is what is shown below as given by AI from my Internet search, correct? (This was my second time doing a quick search and I probably didn’t word the question exactly the same each time, but I thought the first time it included another manufacturer in the list, possibly at the second entry. But I didn’t save it, so might be imagining that.) I’m also curious as to how the 0.5mm leads were used between 1939 and 1962. Just lead holders? (I don’t recall ever seeing any that would hold such small diameter leads.)

I’m also going to let you play the guessing game, since I doubt I will ever win the other one! Below are partial images of the 0.5mm pencil that inspired this search. Does anyone recognize it?

• 1939: A variety of thin lead sizes, including 0.5mm, began appearing on the market.

• 1962: Pentel launched the first mechanical pencils with 0.5mm and 0.7mm polymer leads. This marked a significant change as it introduced a stronger lead made with a polymer binder instead of clay, which allowed for thinner diameters without excessive breakage.

• 1967: Faber-Castell followed suit, releasing a 0.5mm mechanical pencil and associated polymer leads.

• 1967: Staedtler also introduced their 0.5mm version and polymer leads that same year.

• 1968: Mitsubishi Pencil released 0.5mm ratchet mechanism pencils.

[drifand]

@SlideRules

1939: A variety of thin lead sizes, including 0.5mm, began appearing on the market.

First time I’ve seen such an early date mentioned for 0.5mm. Which company did this?

As for Mitsubishi, excerpts from their Japanese commemorative books and milestones page says:
1960 - Began exports to the U.S. through Yasutomo & Co., a distributor in San Francisco.

1961 - Twist-propel mechanical pencils (0.7mm, 0.9mm) are released.

1965 - Developed 0.5mm sharp core. Mass production of knock-type mechanical pencils.

1966 - Company celebrates its 80th anniversary.
– Marketing of “Hi-uni” high-quality pencils begins.
– Signed an exclusive agreement with Yasutomo to sell Mitsubishi’s full product line of pencils, mechanical pencils, and related goods. [We] also granted them rights to sell our 0.5mm mechanical pencils. Initially, mechanical pencils and leads were sold under the “DEMI” brand and electric erasers under the “JETRIC JE-9” brand.

[nimrodd]

Pentel released 0.9mm lead in 1960.

[nimrodd]

And 0.3mm in 1968.

[Alan]

This is just the kind of abject nonsense that I have come to expect from generative AI assistants. For example, just a few weeks ago while researching a set of drawing instruments, my search for the owner’s name along with the word “architect” prompted google’s AI to invent a non-existent architect of the same name, along with several public buildings that he had[n’t] designed.

However, there is a case to be made for fine lead predating the 1960s. As I was recently surprised to discover, the “H” leads of the 1820s were essentially the same size as the modern 0.7 mm, and there was an even smaller (albeit little-used) “VH” size that was presumably closer to 0.5 mm, all long before polymers were even a glint in the industrial chemist’s eye.

By the time of my metal lead gauge, VH had fallen out of use, but I will try to measure one of the leads when I get the chance.

[Alan]

I haven’t found any VH lead yet, but I did come across a small wooden tub of Perry’s number 1, which was a size below the “2” on Wolff’s lead gauge.

These measure up as 0.031" in diameter, or 0.787 mm, just slightly wider than Mordan’s H. Of course, the Perry leads are only 14 mm long, or just over half an inch - about the same length as a leftover lead stump from a modern mechanical pencil - as they had to manage without synthetic polymers.

It’s possible that Mordan’s VH lead was even thinner than modern 0.5 mm lead (which according to this Pentel blog post the JIS standard requires to be between 0.55 mm to 0.58 mm). The following description is taken from Hawkins and Mordan’s 1822 patent:

“In describing this our most favourite pencil-holder or port-crayon, we have given no dimensions, because these must ever depend upon the size and length of the pencils or crayons to be used, which may vary from a quarter of an inch, or more, to the one fiftieth of an inch, or less, in diameter, according as the artist may require a bold line, a fine line, or an extremely delicate line; and from three inches or more, to half an inch, or less, in length.”

One fiftieth of an inch is equal to 0.508 mm, so it would not surprise me if VH lead was as thin as this. Considering it was available in the 1820s (and quite possibly even at launch in 1823), this would push the date of the first 0.5 mm lead back by at least 140 years!

In the meantime, my hunt for the elusive VH lead continues…

[Leonov]

At a certain point, this whole thread rang a bell in my mind, as I remembered I had something very weird in my lead cores inventory. It took me some time to retrieve the specific oddity I had in mind, as it was buried deep under layers of other rare & unusual lead cores, but I got it, and now I am able to present it to the community.

In a store about to close forever I visited a couple of times, the very gentle old lady shutting down the family business once and for all told me that, long before selling clothes, the place used to have a section dedicated to stationery; everything left had been relegated to a couple of dusty drawers.

I spare you many details of my archaeology campaign in the shop. Suffice to say that from one of these drawers there came a tiny cardboard box filled with old plastic/bakelite tubes for lead cores, most likely from an age long before the standardisation of thicknesses. This justified the specific range of lead cores I found there. Feast you eyes on the absurdity:

The outer box was labelled for “1.15mm blacklead”, which is per se a very weird diameter, far from all the standards I am used with — the “typical” unusual size in older pencils is 1.18mm, the “uncommon” size is 1.5mm, for which I think I only have one tube of long lead cores, and one designated leadholder, the A.W. Faber-Castell DS-9450 — whereas the content showed as well these crazy sizes of 1.1mm, 1.15mm, 1.2mm, and 1.4mm.

Needless to say, all the contents of the tubes were mixed, so I had to reorganise everything by use of a gauge micrometer, and sometimes decide where to put a piece of lead based on tolerances lower than 0.05mm. Amazing experience, which I would probably not attempt again.

I wonder whether there might be some form of connection between these sizes and @Alan 's Wolff’s gauge.

PS: The glass tube with cork is “just” for 1.18mm, so the outer container makes up for the “boring” diameter.

PPS: @SlideRules I still have no idea about your pencil, but the imperfections at the junction between barrel and tip makes me think… Is it a custom-made model, maybe made with some mother-of-pearl stuff? Is the iridescent hue an artifact of the camera, or a feature of the item? I’d say Japanese custom/artisanal made specimen, but it might well be European…

[SlideRules]

@Leonov

I still have no idea about your pencil, but the imperfections at the junction between barrel and tip makes me think… Is it a custom-made model, maybe made with some mother-of-pearl stuff? Is the iridescent hue an artifact of the camera, or a feature of the item? I’d say Japanese custom/artisanal made specimen, but it might well be European…

I hadn’t even noticed those little bits between the metal tip and the barrel. As far as I know the pencil is all original and isn’t custom made. Pretty sure it is just plastic, not mother-of-pearl, and the iridescent hue is a feature of the pencil. (A couple more pics with better natural light below.) Good guesses, but neither is correct.

[Alan]

@Leonov

In a store about to close forever

For some reason, I never seem to stumble upon these ancient stationery troves in soon-to-be-shuttered stores, in spite of living in the land of Dickens’ Old Curiosity Shop. However, I applaud your success in this arena; context is everything when it comes to oddities such as these.

I don’t doubt that you are correct to suggest a connection between the plethora of old British lead sizes and your “blacklead” containers. The use of a comma as decimal separator on some of the tubes supports a European origin, and some of the more eccentric diameters seem to be rounded from older sizes (1.15 would equate to a size 5; 1.2 a size 6; 1.4 a size 7). It’s as if the little corner shop was attempting to serve those customers who kept bringing in their odd-sized foreign pencils that none of the usual leads seemed to fit.

It would be interesting to know who made this variety of leads, and whether they simply measured actual specimens to arrive at the sizes. Often the sizes quoted do not reflect the exact diameter of the lead anyway. For example, the “boring” 1.18 mm lead seems to have been introduced by Yard-O-Lead as 3/64" in diameter, yet this converts to 1.190625 mm which in no way rounds to 1.18. This fact only became apparent to me while investigating the bizarre directions that accompanied my Belfor Clicker pencil to “USE ONLY BELFOR CLICKER REFILL LEADS (1.19mm) WITH THIS PENCIL”:

At first I just assumed they were being deliberately incompliant in the hope that customers would keep buying their proprietary refills, but it seems they may have had a point!

I suppose we should also think of it from the pencil manufacturer’s perspective, in the days before standardisation. Was there really any benefit to creating a pencil that would require its own production of dedicated lead refills? For the AW Fabers of this world, the answer may have been yes, but there was still no guarantee of success (the similarly dominant Winsor & Newton attempted to introduce hexagonal artists’ leads in the 1850s, but these sank without trace). For most, it was far better to piggyback on an existing lead size, even if that meant giving business to a competitor.

It makes Mordan’s achievement of the 1820s all the more impressive. Not only did he and Hawkins devise an entirely new category of pencil, but they also introduced an whole ecosystem of prepared leads to accompany them. In retrospect it seems a huge commercial gamble, but somehow it paid off, and their VS leads (about 1.5 mm) were still going strong more than a century later.

[Alan]

As for @SlideRules pencil, it has me completely baffled. I notice from the photo in the original post that the part above the clip seems to flare out, as was common in the earlier 20th century. However, the rest of the pencil looks more modern to me, maybe 1970s. Could it be the product of a legacy pencil maker moving into the fineliner market - Scripto maybe?

[SlideRules]

Good guess! Not SCRIPTO, but getting close! I actually don’t know its age, which is part of the reason I was curious about 0.5mm lead. Here is a full pic showing the other side.

[Alan]

That’s one big eraser! Now I’m going to suggest EFA/Eberhard Faber, partly because of that firm’s liking for supersized erasers, partly because I have seen other EFA pencils with rings around the point.

[Leonov]

Mmm.. Let’s add one more name to the possible list: Eagle / Berol / Turquoise — the latter being just as a not-so-veiled pun with respect to the colour of the item… (the imprint on the barrel seems quite “primitive”, but fascinating nonetheless).

I’d even say “Alvin”, but it is probably too young a manufacturer…

[Alan]

I’m also not sure that Alvin made any of their own things. Certainly Alvin drawing instrument sets were all rebadged versions by other makers.

[SlideRules]

Good guesses and observations! Getting really close! I just came across another pencil online by the same maker with the same body shape. It is dated 1974, although it isn’t the same lead size.

[drifand]

The body shape reminds me of some of Autopoint’s Jumbo models… but the flared eraser holder is pretty unique!

[SlideRules]

You’re getting closer! The printing also made me think of some of the Autopoint pencils. Here’s a hint:

“I have been, and always shall be, your friend.”

[drifand]

Eversharp!

[SlideRules]

No, not Eversharp…I guess my hint wasn’t as good as I thought!

“The needs of the many outweigh the needs of the few, or the one.”

[DarkwingDuck]

Do anyone say Skilcraft?
The print looks exactly like the US Government print