Pentel Refill Leads. Extra strong, hard wearing, dense, hi-polymer leads, suitable for use on all paper, tracing and drafting media. 0.5mm. Grade - HB. The Pentel 0.5MM Grade HB Super Hi-Polymer Leads are from the high-performance family and are Stronger and darker than regular leads. They have a slower wear rate than usual leads. These leads are suitable for all makes of Pentel mechanical pencil. They are Ideal for writing and drawing on Paper, tracing paper and card. Each tube is made from 100% recycled material and contains 12 leads. Extra strong, hi-polymer leads for all paper, tracing and drafting media. Features 0.5mm. 12 Tubes of 12 Leads The UK`s favourite refill lead Ideal for paper, tracing and drafting media Extra strong, slow wear rate, dark colour Suitable for all Pentel automatic pencils Made from 100% recycled material (excludes refill leads).