Abstract: An extension for pencils with wearing leads, formed from a thin-walled hollow profile. The inner cross section is adapted to the shape of a pencil. One or more slots of appropriate length in the longitudinal direction at an end of the extension where the tapered end of the pencil is located and a slight linear reduction in the cross section approximately over the length of one or more slots. Longitudinal raised sections in the form of triangular, square, and/or semi-circular prisms, directed inwardly. The height of the raised sections may increase in the direction of insertion of the pencil and dig into the pencil slightly when the pencil is inserted. The height of the raised sections is reduced linearly to zero at the end of the extension where the pencil is inserted. Inwardly bent or protruding retaining springs arranged on the inner surface of the extension.

Abstract: An extension for pencils with wearing leads, formed from a thin-walled hollow profile. The inner cross section is adapted to the shape of a pencil. One or more slots of appropriate length in the longitudinal direction at an end of the extension where the tapered end of the pencil is located and a slight linear reduction in the cross section approximately over the length of one or more slots. Longitudinal raised sections in the form of triangular, square, and/or semi-circular prisms, directed inwardly. The height of the raised sections may increase in the direction of insertion of the pencil and dig into the pencil slightly when the pencil is inserted. The height of the raised sections is reduced linearly to zero at the end of the extension where the pencil is inserted. Inwardly bent or protruding retaining springs arranged on the inner surface of the extension.