Since their beginnings in the early 19th century, the mechanical pencil (sometimes called a propelling pencil) has come a long way. With advancements in technology allowing for stronger, more robust ‘leads’ and continual improvements to the internal gripping mechanism, mechanical pencils have become the handy go to for all occasions; enabling both technical precision, and artistic flair.
Mechanical pencils have diversified over the years to hold a range of different lead sizes. The lead size will affect what your pencil will be best for.
We have outlined the 10 most commonly used lead sizes for mechanical pencils; what they look like, feel like, what they are good for and which products you should choose for this size lead. 
This picture shows the line widths of lead sizes from 0.3mm to 5.6mm.
0.3mm leads are the thinnest of the lead sizes currently available. As this size is generally used for technical drawings and finer details they are usually available in HB or harder, but softer graded leads can be found. The 0.3mm HB was hard to write with, as there was no give in curves. This size was excellent for drawing straight lines, especially when aided by a ruler. The effect was clean and precise.
Our Pick:
Platinum Pro-USE MSD 1000A 0.3mm Pencil
The narrow barrel and thin writing point make this an ideal pencil for professional drafting as they enable an uninterrupted view of the drawing.
This is a popular lead size with many companies creating mechanical pencils designed for 0.5mm leads. However several companies have recently changed their standard size from 0.5mm to 0.7mm e.g. Cross. The fine line is suitable for both writing and technical drawing. Like 0.3mm leads these are more commonly found in HB and harder.
Our Pick:
Ohto Promecha Mechanical Pencil
The aluminium and steel construction makes this pencil lightweight, but perfectly balanced. Whilst the rubber grip section which twists to set the exposed lead length makes this pencil a joy to use.
0.7mm is the most common lead size used for mechanical pencils. The writing style matches closely to the size of a fine ballpoint or rollerball, and is available in the widest array of hardnesses. The lead thickness is great for day to day writing, sketching and can be used for less detailed technical drawings. Very pleasant to use.
Our Pick:
Faber-Castell Ambition Pearwood Pencil
The sumptuous wood barrel of the Faber-Castell Ambition Pearwood coupled with the highly polished chrome trim makes this pencil a statement piece with real wow factor. Faber-Castell have a true pedigree when it comes to making fine writing instruments, with origins in the beginning of the 20th century and this pencil.
0.9mm leads are similar to a medium width writing point pen. 0.9mm was the standard size for mechanical pencil leads from the late 1940’s till around 1980. The size allows for writing and drawing strong, solid lines and lends itself well to sketching.
Our Pick:
Kaweco Special 0.9mm Push Pencil
The light and robust Kaweco Special has a balanced feel and suits both writing and drawing. The elongated writing point allows for the user to easily view what they’ve just put onto paper.
1.18mm (Sometimes known as 1.1mm or 1.2mm) were the standard size for mechanical pencils way back when they first became popular. As this size was used in the very first Yard-O-Led pencils, the company has made a conscious decision to maintain the size throughout the years. This size is similar to a broad point pen, and can feel slightly cumbersome for smaller handwriting.
Our Pick:
Worther Slight Mechanical Pencil Available in Black Aluminium or Natural Aluminium
This sleek lightweight pencil has a modern feel and is simple to use, with the writing point twisting to extend and retract the lead. This pencil also refills through the writing point opening so there are no loose bits to lose or break.
1.4mm is the last size of lead that is really suitable to write with. Past this width the letters can be difficult to draw and need to be simplified to ensure they are legible, however this does mean that 1.4mm leads are perfect for young children as it encourages them to write large clear letters. The lead width also ensures a solid and consistent line.
Our Pick:
Lamy ABC Pencil Available in Blue or Red
Designed for little hands, this pencil features an ergonomic grip to encourage correct finger placement and a robust wood and plastic shell. The included stickers enable you to label your pencil and ensure they don’t go walkies.
From 2.0mm upwards your lead may need sharpening in order to get the effect you are after. The 2.0mm size is cumbersome and was not pleasant to write with, but to sketch it was a pleasure. Great for shading. Press hard for strong dark lines and softly for smooth shades.
Our Pick:
Kaweco Special ‘S’ 2.0mm Push Pencil
Easy to use push mechanism and compact, durable aluminium body will make this your go to sketching pencil for carrying around in your bag or pocket.
These two lead sizes are so similar it is hard to tell them apart. 3.0mm and 3.2mm leads usually come sharpened in the pencil and will need to be sharpened depending on your preference. This size is great to sketch with and for shading. Press hard for strong dark lines and softly for smooth shades.
Our Pick:
Worther Shorty Available in a wide range of colours, including Green, Purple and Black
Cheap and inexpensive, but a thoroughly pleasurable writing experience. The Worther Shorty is has a durable plastic exterior and comes with a manufacturer lifetime guarantee. Due to their superior German craftsmanship, the Shorty has a cult following in the art and design world.
The largest of the common lead sizes. This chunky sized lead will need regular sharpening. It’s prowess lies in shading and sketching larger objects. Press hard for strong dark lines and softly for smooth shades.
Our Pick:
Worther Compact Mechanical 5.6mm Pencil Available in Black Aluminium or Natural Aluminium
This great sketching pencil comes fitted with 4B leads, perfect for sketching. Plus, this pencil comes with its own sharpener so you can ensure your pencil is always just so.
The picture below was drawn using all of the aforementioned lead sizes.
