ISO 9177-3:1994 PDF Download

Specifically addressing the black leads used in mechanical pencils for technical drawings, ISO 9177-3:1994 is a standard. The goal of the standard is to identify the bending strengths of HB leads, which are frequently found in mechanical pencils.

The standard specifies the bending strength of these leads, which is a crucial quality to guarantee their robustness and lifetime. The standard guarantees that producers can precisely determine the bending strength of the HB leads they produce by providing a uniform testing procedure.

The leads' resistance to breaking or bending while in operation is determined by their bending strength, which is an important consideration. The standard serves to ensure that mechanical pencils with HB leads meet certain quality criteria by establishing standards for this feature, allowing consumers to rely on the performance and durability of their mechanical pencils.