At a glance: 2026 effective dates
| Effective date | Domain | Key standards |
|—————-|——–|—————|
| 2026-01-01 | Couplings | GB/T 14653-2025 (flexible rod couplings) |
| 2026-03-01 | Gears | GB/T 12368-2025 (bevel gear modules) |
| 2026-05-01 | Belt drives | GB/T 10412-2025, GB/T 46597-2025, GB/T 13487-2025 |
| 2025-10-01 | Couplings | GB/T 5843-2025 (flange couplings) — already in force |
> Note: Not all listed standards share the same implementation date. Always confirm the implementation date on the official standard record before using a standard in contracts or inspection plans.
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Quick reference table
| Standard | Product / scope | Published | Effective | Replaces | ISO alignment |
|———-|—————–|———–|———–|———-|—————|
| GB/T 10412-2025 | Classical & narrow V-belt pulleys (datum width system) | 2025-10-31 | 2026-05-01 | GB/T 10412-2002 | Mod. ISO 4183:1995 |
| GB/T 46597-2025 | Grouped classical V-belt pulleys AJ, BJ, CJ, DJ, EJ (effective width system) | 2025-10-31 | 2026-05-01 | — (new) | Mod. ISO 5291:2011 |
| GB/T 13487-2025 | General-purpose rubber synchronous (timing) belts | 2025-10-31 | 2026-05-01 | GB/T 13487-2017 | — |
| GB/T 12368-2025 | Bevel gear modules (straight & helical) | 2025-08-29 | 2026-03-01 | GB/T 12368-1990 | Mod. ISO 678:1976 |
| GB/T 5843-2025 | Flange couplings | 2025-03-28 | 2025-10-01 | GB/T 5843-2003 | — |
| GB/T 14653-2025 | Flexible rod couplings | 2025-06-30 | 2026-01-01 | GB/T 14653-2008 | — |
Official records: National Public Service Platform for Standards Information · GB standards open platform
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1. Belt pulleys & belt drives — three standards effective May 2026
On 1 May 2026, three GB/T standards in belt transmission take effect together. Together they cover classical V-belt pulleys, grouped V-belt pulleys, and general synchronous belts.
GB/T 10412-2025 — Classical and narrow V-belt pulleys (datum width)
– Scope: Groove profiles, datum diameter series, groove inspection, pulley material, surface roughness, and balance for single-belt classical and narrow V-belt pulleys (types Y, Z, ZX, A, AX, B, BX, C, CX, D, E and SPZ, XPZ, SPA, XPA, SPB, XPB, SPC, XPC).
– Not covered: Pulleys for grouped (banded) V-belts — see GB/T 46597-2025.
– Buyer impact: Drawings and inspection sheets should reference the 2025 edition after the effective date. Groove dimensions and inspection methods may differ from legacy GB/T 10412-2002 parts still in stock.
GB/T 46597-2025 — Grouped classical V-belt pulleys (effective width)
– Scope: AJ, BJ, CJ, DJ, and EJ groove profiles for grouped classical V-belt applications under the effective width system.
– Buyer impact: Complements GB/T 10412-2025 by separating single-belt and grouped-belt pulley rules—reducing ambiguity in RFQs and incoming inspection.
GB/T 13487-2025 — General-purpose synchronous belts
– Scope: Classification, structure, materials, marking, technical requirements, test methods, and packaging for general industrial synchronous (timing) belts.
– Not covered: Automotive synchronous belts.
– Buyer impact: Relevant when pairing timing pulleys with rubber synchronous belts in general machinery—not for automotive engine timing systems.
Explore NDS pulley products: Belt pulleys · Timing pulleys
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2. Gears — bevel gear module standard effective March 2026
GB/T 12368-2025 — Bevel gear modules
– Published: 2025-08-29 · Effective: 2026-03-01
– Administration: SAC/TC 52 (National Gear Standardization Technical Committee)
– Scope: Module series for straight and helical bevel gears in civil and industrial applications; spiral bevel and hypoid gears may refer to this standard where applicable.
– ISO alignment: Modified adoption of ISO 678:1976.
– Buyer impact: Module selection, tooling, and interchangeability for bevel gear pairs should follow the 2025 module table in new designs after March 2026.
Explore NDS gear products: Gears
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3. Couplings — two standards in the 2026 cycle
GB/T 5843-2025 — Flange couplings (already effective)
– Effective: 2025-10-01
– Scope: Basic parameters, main dimensions, technical requirements, testing, and packaging for flange couplings with nominal torque 80 N·m to 180,000 N·m.
– Administration: SAC/TC 109
GB/T 14653-2025 — Flexible rod couplings
– Effective: 2026-01-01 · Replaces GB/T 14653-2008
– Scope: Flexible rod couplings requiring angular and/or axial misalignment compensation, operating temperature −30 °C to 120 °C.
– Administration: SAC/TC 137 (ship machinery committee)—often used in marine and heavy-duty contexts; verify applicability for your industry.
Explore NDS coupling products: Couplings
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What these updates mean for global buyers
1. Closer alignment with ISO
Several 2026 standards modify ISO bases (e.g. ISO 4183, ISO 5291, ISO 678). For exporters and OEMs selling into multiple markets, this supports consistent groove geometry, module series, and inspection language between Chinese manufacturing and international catalogs—provided drawings explicitly cite the correct GB/T edition.
2. Finer-grained standard families
Belt drive rules now split single-belt vs grouped-belt pulleys instead of one broad document. Expect clearer RFQ specifications, fewer disputes over which groove system applies, and more precise incoming QC checklists.
3. Practical sourcing and QA actions
– Update approved vendor lists and drawing notes to reference 2025-edition GB/T numbers where applicable.
– Segregate legacy inventory labeled to superseded standards (e.g. GB/T 10412-2002) until groove inspection confirms compatibility.
– Ask suppliers for material certificates, balance grade, and groove inspection reports aligned with the new editions.
– Do not assume one coupling standard covers all industries—check TC scope (general machinery vs marine).
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Summary
2026 is a meaningful year for China’s transmission component standards: belt pulley and synchronous belt rules refresh in May, bevel gear modules in March, and flexible rod couplings from January, while flange coupling requirements are already updated. For overseas buyers, the headline is not “new law”—it is clearer, ISO-aligned technical baselines for specifying and accepting pulleys, gears, and couplings from Chinese manufacturers.
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Need pulleys, gears, or couplings built to current standards?
NDS (Shandong Nuodis Machinery Equipment Co., Ltd.) manufactures belt pulleys, gears, sprockets, and couplings for industrial OEM and export applications. Share your drawing, standard reference, or application details and our team will confirm material, groove profile, and inspection approach.
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Disclaimer
This article is provided for general technical reference only. It is not legal advice, certification, or an official interpretation of Chinese national standards. For compliance decisions, consult the published standard text and qualified engineers in your jurisdiction. NDS is a manufacturer, not a standards body.
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*Last updated: June 2026*
