Different sizes of lead diameters are available to accommodate various preferences and pencil builds. The more common lead sizes are 0.5 mm and 0.7 mm, whose line widths provide a favourable balance between precision and strength. Less common lead sizes can range from 0.2 mm up to 5.6 mm. As with non-mechanical pencils, the leads of mechanical pencils are available in a range of hardness ratings, depending on the user's desired balance between darkness and durability.
EndlessPens have curated a collection of various lead refills with a range of diameters, lead grades / hardness and erasers for your mechanical pencil needs.