标准摘要
[中文适用范围]： 本标准规定了技术制图自动铅笔用HB硬度黑铅的弯曲强度和试验方法。 [外文原描述]： This document specifies bending strengths and a test method for black leads of HB hardness degree used for mechanical pencils for technical drawings.
英文名称Mechanical pencils for technical drawings — Part 3: Black leads — Bending strengths of HB leads