GB/T 21684-2025Four-side moulding machines for woodworking - Vocabulary and accuracy (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 supersedes GB/T 21684-2008 "Terminology and Precision of Two-, Three-, and Four-Sided Milling Machines for Woodworking Machines" and is consistent with GB/T 21684- Compared to.2008, aside from structural adjustments and editorial changes, the main technical changes are as follows:

---The normative references have been changed (see 4.2,

4.7 and Table 1; 3.2,

3.7 and Table 2 in the.2008 edition);

---The terminology has been changed to "Terminology and Definitions," and the example diagram of the four-sided woodworking milling machine and related technical content have been revised (see Chapter 3). Chapter 4 of the.2008 edition);

---The phrase "Brief Description" has been changed to "General Requirements," and the relevant content descriptions have been revised (see Chapter 4, Chapter 3 of the.2008 edition);

---The inspection methods in the geometric accuracy inspection items have been changed (see Chapter 5, Chapter 5 of the.2008 edition);

---The simplified diagram and inspection items in geometric accuracy inspection item 16 have been revised (see Table 1, Item 16, Chapter 5,.2008 edition). G16);

---The work accuracy check has been removed (see

5.2 in the.2008 version). Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed by the China Machinery Industry Federation. This document is under the jurisdiction of the National Technical Committee on Standardization of Woodworking Machine Tools and Cutting Tools (SAC/TC84). This document was drafted by: Fujian Provincial Academy of Mechanical Sciences, Guangdong Institute of Product Quality Supervision and Inspection, and Guangdong Ruiya Machinery Co., Ltd. Foshan Shunde Fuhao Woodworking Machinery Manufacturing Co., Ltd., and Foshan Shunde Wokneau Machinery Co., Ltd. The main drafters of this document are. Song Ting, Yin Zhihong, Zhou Huabiao, Wang Heping, Jiang Taiwu, and Wang Can. The release history of this document and the document it replaces is as follows: This document was first published in.2008, and this is its first revision. Terminology and Precision of Four-Sided Wood Milling Machine

1 Scope

GB/T 21684-2025 is the Chinese national standard on four-side moulding machines for woodworking - vocabulary and accuracy, in the field of wood technology. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 31 October 2025 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 May 2026. Classification: ICS 79.120.10, CCS J65. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document defines the terminology for four-sided woodworking milling machines and their main components, specifies the geometric accuracy inspection and corresponding tolerances, and describes the relevant... The corresponding test method. This document applies to the precision inspection of general-purpose, ordinary-precision four-sided wood milling machines. This document is not applicable to operational tests of four-sided woodworking milling machines (such as inspections for vibration, abnormal noise, and component creep), nor is it applicable to... Machine tool characteristic inspection (such as speed, feed rate, etc.).

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 17421.1-2023 General Rules for Machine Tool Inspection - Part

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 A woodworking planer and/or milling machine that performs simultaneous machining on four sides of a workpiece in a single feed. The machine tool has at least four machining heads, distributed in... It has a rotating planer or milling cutter in four positions. top, bottom, left, and right.

Note. The main components of the machine tool and their names are shown in Figures 1 and 2.

3.2 mainframe;body The main frame structure or main bed components in the bed section.

3.3 workbench table A component with a working plane for supporting and clamping workpieces.

3.4 Vertical cutter axis cutter block miling Vertically mounted planer shaft.

3.5 guide plate fence A plate-shaped component used to guide the workpiece to move in a certain direction; there is relative motion between it and the workpiece during feeding.

3.6 Table roller A cylindrical rotating component on the worktable that supports the workpiece.