GB/T 43550.1-2023Mechanical pencils and leads for general use - Classification, dimensions, quality and test methods - Part 1: Mechanical pencils (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting:

This document is Part 1 of GB/T 43550 "Classification, Dimensions, Quality and Test Methods of Mechanical Pencils and Leads for General Purposes":

GB/T 43550 has published the following parts:

---Part 1: Mechanical Pencil;

---Part 2: Black lead core:

This document is equivalent to ISO 20318-1:2019 "Classification, Dimensions, Quality and Test Methods for Mechanical Pencils and Leads for General Purposes" Part 1: Mechanical Pencils:

Please note that some content in this document may be subject to patents: The publisher of this document assumes no responsibility for identifying patents:

Introduction

Mechanical pencils are one of the most popular writing tools among consumers: In recent years, general-purpose mechanical pencils have become increasingly popular among students:

Welcome, and with different use occasions, the types of lead core hardness and diameter are also increasing: It is worth noting that the mechanical pencil presents an overall the output is increasing year by year, but the output of mechanical pencils used for technical drawing is on a downward trend: Scope of application of GB/T 39542 (all parts) the scope is limited to technical drawing mechanical pencils and lead: Because it is different from technical drawing mechanical pencils and lead, it is necessary to make a formula suitable for general use:

Standard for mechanical pencils and lead:

GB/T 43550 "Classification, Dimensions, Quality and Test Methods of Mechanical Pencils and Lead Leads for General Purposes" is intended to consist of two parts:

---Part 1: Mechanical Pencil: The purpose is to establish quality requirements and test methods suitable for general-purpose mechanical pencils:

---Part 2: Black lead core: The purpose is to establish quality requirements and test methods for black lead cores for general-purpose mechanical pencils:

Since the release of the standard for mechanical drawing pencils and lead cores, two issues have not been resolved: One is mechanical pencil and lead packaging the markings on the product indicate that lead cores with nominal diameters of 0:35mm and 1mm are marked as 0:3mm and 0:9mm respectively: This paper attempts to accurately determine Define the diameter to solve the sign problem: Second, there is currently no scientific definition of hardness grade: Although this paper attempts to establish a purely quantitative assessment methods, but qualitative assessment is still needed: This issue is not addressed in this paper:

General purpose mechanical pencils and lead classifications, sizes, Quality and test methods Part 1: Mechanical pencils

1 Scope

This document specifies the classification, size, and quality requirements for handheld general-purpose mechanical pencils that can hold and output lead, and describes the corresponding test methods:

This document applies to general-purpose mechanical pencils and to multi-function pens equipped with a mechanical pencil unit:

This document does not apply to pencils included with mechanical instruments such as plotters:

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, the dated quotations for undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document:

ISO 20318-2 Classification, dimensions, quality and test methods for mechanical pencils and lead for general use Part 2: Black lead (Me-2:Blackleads) Note: GB/T 43550.2-2023 Classification, dimensions, quality and test methods of mechanical pencils and lead for general use Part 2: Black lead (ISO 20318-2:2019,IDT)

3 Terms and definitions

The terms and definitions defined in ISO 20318-2 and the following apply to this document:

ISO and IEC maintain terminology databases used for standardization at:

---ISO online browsing platform: available from https://www:iso:org/obp;

mechanical pencil mechanical pencil A handheld writing instrument capable of holding and delivering lead:

multi-functionpen Writing consisting of two or more writing units (mechanical pencil unit and neutral ink ballpoint pen or ink ballpoint pen refill) tool:

NOTE: At least one writing unit is a mechanical pencil:

markingdiametermarkingdiameter A number used to classify lead cores by their thickness (diameter):

Note: Corresponds to the mechanical pencil lead classification specified in ISO 20318-2: