The standard system of the plastic mold industry mainly consists of national standards, mechanical industry standards and association standards, covering the whole process from basic terminology to design, manufacturing and acceptance. National standards serve as the general basic specifications for the industry, mechanical industry standards focus on specific parts and process requirements, and the latest association standards are more in line with the actual industrial application and have gradually become the mainstream implementation standard for core components such as mold bases.
1. Basic General StandardsThese standards are the foundation of mold design, communication, drawing specification and acceptance, and are essential guidelines for all practitioners.
GB/T 8846-2005 Plastic Molding Molds - Vocabulary unifies professional terms in the industry to ensure consistent language and avoid ambiguity in design, production and communication.
GB/T 14486-2008 Technical Conditions of Plastic Molds specifies the general requirements for the whole process of molds from design, material selection, processing, precision control, assembly and commissioning to marking, packaging, transportation and storage.
GB/T 12555-2006 Design Specification for Plastic Injection Molds is the core specification for injection mold design, detailing technical requirements for key design links including mold structure, parting surface design, gating system, ejection system, cooling system, venting system, and guiding and positioning mechanisms.
GB/T 47067-2026 Plastics Moulded Parts - Tolerances and Acceptance Conditions will be officially implemented on August 1, 2026 as the latest standard for plastic part tolerances, replacing the old version and becoming the core basis for acceptance of dimensional tolerances, geometric tolerances, appearance and performance of plastic parts.
GB/T 1804-2000 General Tolerances - Tolerances for Linear and Angular Dimensions Without Individual Tolerance Indications and GB/T 1184-1996 Geometrical Tolerances - Tolerances Without Individual Tolerance Indications are the implementation basis for unspecified tolerances of mold parts, regulating dimension requirements not separately marked on drawings.
2. Mold Base and Component StandardsMold bases and standard parts are basic components of molds, and their standardization directly affects production efficiency and interchangeability. T/CDMIA B013-2025 Technical Specification for General Plastic Injection Mold Bases is the latest association standard issued by the China Die & Mould Industry Association, implemented on March 28, 2025, specifying the structure, parts, assembly, precision, inspection, acceptance and packaging of mold bases, and gradually replacing old national standards as the mainstream standard for mold base procurement and acceptance. GB/T 12556-2006 Technical Conditions of Plastic Injection Mold Bases is an old national standard still referenced by some enterprises and used alongside the new association standard. GB/T 46157-2025 Molds for Plastics - Shouldered Ejector Pins specifies dimensions, tolerances, materials, hardness and marking of shouldered ejector pins, equivalent to the international standard ISO 8694. JB/T 8062-2016 Guide Pins for Plastic Injection Molds and JB/T 8063-2016 Guide Bushings for Plastic Injection Molds define the dimensions, precision, materials, hardness and matching requirements of guide pins and bushings as core standards for guiding and positioning systems. JB/T 7654-2016 Sprue Bushing for Plastic Injection Molds specifies the structure, dimensions, precision and materials of sprue bushings as a key component standard for gating systems.
3. Manufacturing and Acceptance StandardsThese standards are the core basis for quality control and delivery acceptance of molds, directly determining the final quality and service life. GB/T 30731-2014 Quality Standard for Molds in Machinery Industry and GB/T 30732-2014 Specification for Mold Manufacturing and Acceptance stipulate general specifications for mold manufacturing, precision testing, assembly, test molding and acceptance as the foundation of quality control. GB/T 14663-2024 Technical Specification for Plastic Encapsulation Molds is a special standard for plastic encapsulation molds, defining requirements for structure, safety, performance, parts, assembly, inspection and acceptance. GB/T 41345-2022 General Technical Requirements for Compression Molds for Plastic Bottle Caps specifies special technical requirements for compression molds of plastic bottle caps, applicable to their design, manufacturing and acceptance.
4. Material StandardsMold material selection directly affects service life, cost and molding quality, with relevant standards as the core basis for material selection. GB/T 1298-2021 Tool Steels and GB/T 1299-2021 Alloy Tool Steels specify the chemical composition, mechanical properties, hardness and heat treatment requirements of commonly used mold steels, serving as the core basis for material selection. GB/T 20044-2008 Metallic Materials - Heat Treatment Code - Annealing Code for Hot Rolled Steels provides implementation guidelines for mold steel heat treatment to ensure stable material performance.
5. Core Technical RequirementsPrecision Requirements
Mold base precision is divided into general, precision and ultra-precision grades, corresponding to parallelism, perpendicularity, coaxiality and parting surface clearance. Precision-grade parallelism does not exceed 0.02mm per 300mm. Dimensional tolerances of key molded parts are controlled within ±0.01 to ±0.05mm, geometric tolerances within 0.02mm, and general parts comply with medium unspecified tolerances. Precision plastic parts have tolerances of ±0.02 to ±0.05mm, and general parts ±0.1 to ±0.3mm.
Surface Quality Requirements
Molded surface roughness varies by precision grade: Ra ≤ 0.8μm for general parts, Ra ≤ 0.4μm for precision parts, Ra ≤ 0.2μm for mirror-finished parts, with no scratches, pits, pores or cracks. Non-molded surfaces have Ra ≤ 3.2μm, chamfered and deburred without sharp edges.
Assembly and Operational Requirements
The guiding and positioning system has a guide pin-bushing clearance of 0.01 to 0.03mm, smooth movement without jamming, reliable positioning, and parting surface fitting clearance ≤ 0.02mm. The ejection system operates smoothly with accurate reset and balanced ejection. Cooling or heating systems have unobstructed channels without leakage, and hot runner systems ensure precise temperature control.
Test Molding and Acceptance Requirements
General molds require 1 to 3 test runs, complex molds no more than 5, with finished parts free from defects. General molds have a service life of at least 300,000 cycles, precision molds 500,000 to 1 million cycles. Acceptance is based on 3D drawings, technical agreements, national standards and test samples, confirmed by both parties.
6. Standard Application and Quotation RelevanceQuotations are based on standards to determine material grade, precision, component specifications, processing, test runs and service life. Contracts must specify standards, precision, surface requirements and acceptance terms to avoid disputes. Precision-grade molds cost 20% to 50% more than general-grade, imported standard parts 30% to 100% more than domestic, and mirror polishing 50% to 100% more than ordinary polishing.
7. Access to StandardsNational standards are available on the National Standard Information Public Service Platform, industry and association standards through official websites of industry associations, and large enterprises have internal standards higher than national standards for high-end products.
