I'm guessing this is because 2mm leads are clay-bound and unlike polymer the recipe is 'traditional' to each manufacturer. I know they're not really in the mainstream of Dave's interest, but something possibly interesting is the apparent variation of hardnesses between manufacturers. With a harder lead I seem to press too hard (without being aware) in order to get a blacker line.Īs a separate matter, I've been experimenting with the vintage pleasures of 2mm clutch pencils. I've found that using a softer lead than my default choice (ie use B or even 2B instead of HB) makes me press less hard and break leads less often. Which is too bad, because the pencil is just a bit less useful if it requires a specialty size refill. Next I tried the art supply store lead, which I somehow think would have to conform to the 5.6mm standard - and it wouldn't go in the Leonardo! I put in the Bexley lead - and there were no problems at all. I haven't actually changed the Leonardo's lead previously. I can't visually see any difference amongst them, and don't have any way of measuring 1/10th of a millimeter. I also have some leads from Bexley (for the Multi-Max) that are not labelled as to dimension, and some no name leads from art supply stores. So maybe 5.6mm isn't as much of a standard as So I remembered a box of Koh-I-Noor 5.6mm leads I have - and lo and behold, they are labelled '5,45 mm'. Looking at the Leonardo instruction booklet, it does say 5.5mm, and a Montblanc refill tube is labelled: Leads of 2mm and over are usually for use in clutch mechanism pencils – leadholders, clutch pencils, sketch pencils or whatever you prefer to call them. For instance, I believe that the standard 2mm leads sold by Staedtler and Faber-Castell are just their normal wood pencil ceramic leads (without the wood!). In between it’s a mixture, but mostly polymer. I think it’s safe to say that under 1mm they are all polymer leads, and 2mm and over are all ceramic leads. Somewhere in the 1 to 2mm range they usually change. Most manufacturers offer far fewer grades.Īnother point of interest is the change from ceramic to polymer leads. For instance in 0.5mm Pentel offer 12 grades, but only 5 grades in 0.9mm. Other diameters have considerably less selection of brands and hardness’s. But thats variable, one manufacturer marks some of their HB pencils as #2 and some as #2 ½ !?Ġ.5mm and 0.7mm are unquestionably the most common lead diameters and have a wide range of hardness grades available. As a rough guide, for the USA, #1 = B, #2 = HB, #2 ½ = F, #3 = H and #4 = 2H. From the softest darkest through to the hardest lightest lead, the range is usually 6B up to B, then HB, F, and H up to 6H, but some manufactureres may go from about 9B through to 10H.

Slightly darker and softer is B, which is about #1. The standard writing grade is usually HB, which is about #2 in the USA. So HB grade is Hard Black, 6B is extremely soft and dark, 4H is very hard and light. The more H's in the designation the lighter (and harder) the lead, and the more B's the softer and darker. In the middle there is also an F (for Firm). Leads are often called #1, #2 etc in the USA, but most of the rest of the world uses the 'HB' system. There is no real standardisation of lead hardness or darkness. Confusing, but in general with these “variable” leads the differences don’t seem to matter as they are all the same thickness or the pencil mechanisms involved can handle the differences. Faber-Castell lead refills are marked 1.0(0.9) and 0.35(0.3), but Pentel mark theirs the other way around, 0.3(0.35). For example my Rotring Tikky 1.0 takes a 0.9mm lead.

For example 0.3mm lead is usually 0.35mm just rounded down 1.1mm and 1.2mm are usually 1.18mm rounded down or up, but sometimes 1.1mm is really 1.1mm as distinct from 1.18mm. Many of them started out as imperial fractions of an inch so the metrication of them also produced rounding. One problem is that some sizes are frequently rounded up and/or down to another number, without any consistency, so you are sometimes unsure what diameter you really have. The lead in ordinary wood pencils is usually about 2mm = 0.0787 inches = a little under 1/12th inch. A common writing size is 0.5mm = 0.0197 inches = about 1/50th of an inch. Nowadays mechanical pencil lead diameters are all measured in metric. Lead sizes are designated by their diameter, in millimetres (mm).Ġ.3mm / 0.35mm (Usually the same thing, just rounded down to 0.3)Ġ.5mm (The common fine writing thickness)Ġ.7mm (Common writing thickness, stronger than 0.5)ġ.18mm / 1.1mm / 1.15mm / 1.2mm (Usually the same - a whole lot of different rounding values for the same stick of lead!) Standard Mechanical Pencil Lead Sizes (diameters) (Currently In Common Use)

I have been prompted to publish this posting by people finding this blog with searches indicating they are looking for lists of lead diameters that are currently readily available, and some information on lead grades or hardness.

Papermate mechanical pencil 1.3mm