Mechanical pencils also clutch pencil is with a replaceable and mechanically extendable solid pigment core called a “lead”.
The lead, often made of graphite, is not bond to the outer casing, and mechanically extend as its point is worn away as it is use.
Mechanical pencil is use to provide lines of constant width without sharpening in technical drawing and in quick, neat writing. They use for architectural drawings & fine-art drawing. Since they do not have to sharp, they also very popular with students.
Buy online Lyra Mechanical Pencils from Fine Art Material. Available in 0.5mm, 0.7mm, 0.9mm & 2mm lead thickness.