Gear Accuracy Standards Rewritten: ISO 1328-2:2020 Lands

Summary: ISO 1328-1:2013 and ISO 1328-2:2020 have replaced the 1995/1997 editions and become the new basis for gear export acceptance; the grade cross-reference between DIN 3961~3967, AGMA 2015 and GB/T 10095 is still the common language of quotation. With the Shanghai industrial fair approaching in September, enquiries for precision ground gears are picking up. Geyontech grinding reaches DIN 4-5, and cylindrical gear inspection covers modules M0.5~20 with a maximum outside diameter of 800 mm.

1. Standards Update: ISO 1328 Revised, Export Acceptance Follows the New Editions#

1.1 ISO 1328-1:2013 and ISO 1328-2:2020 Replace the Older Editions#

ISO 1328-1:2013 defines the definitions and allowable values of tooth flank deviations, replacing the 1995 edition; ISO 1328-2:2020 defines radial composite deviations, replacing the 1997 edition. These two standards are the most widely accepted accuracy basis in global gear trade. For orders whose drawings specify “ISO 1328-1:2013 / ISO 1328-2:2020”, acceptance uses the tolerances of the new editions.

1.2 Cross-Reference of DIN, AGMA, GB and ISO Grades#

European customers quote DIN 3961~3967 (DIN 3962 covers pitch, profile and helix tolerances), North America uses the AGMA 2000-A88 Q grades or AGMA 2015 harmonized with ISO 1328, and the domestic market follows GB/T 10095. Approximate grade correspondence: DIN 4-5 ≈ ISO 3 ≈ AGMA 15 ≈ GB 3 (high-precision metrology gears); DIN 5 ≈ ISO 5 ≈ AGMA 13 ≈ GB 5; DIN 7 ≈ ISO 7 ≈ AGMA 11 ≈ GB 7 (automotive gearboxes/general). Aligning the grade system first and discussing tolerance values second saves a lot of back-and-forth.

2. Technical Progress: Grinding and Inspection Parameters Keep Rising#

2.1 Grinding Remains the Standard Operation for High-Precision Gears#

For hard-tooth-surface gears after carburizing and quenching, finishing is essentially done by grinding. Ground gears of ISO 3~5 reach a surface roughness of Ra 0.2~0.4 μm, helix tolerances are taken from DIN 3962, and the values commonly used for grades 5~7 are 6~16 μm. The grinding accuracy grade directly affects gearbox noise and load-carrying consistency. Geyontech grinding reaches DIN 4-5, batch production is controlled to GB 4~5, turning accuracy is 0.005 mm, grinding accuracy 0.001 mm, and the fastest hobbing cycle is 5 s/tooth.

2.2 Inspection Capability Keeps Pace with Accuracy#

Full-item inspection before shipment: profile, helix, cumulative pitch and gear runout on a gear measuring center, then mating gears are re-checked on a meshing tester. Geyontech inspection range: cylindrical gears module M0.5~20, maximum outside diameter 800 mm, maximum face width 400 mm, workpiece 300 kg; bevel gears M1~16, maximum diameter 500 mm, pitch cone angle 5°~90°; worm gear sets M0.5~16, 1~6 starts. Hardness testing covers HRC 20~67, HV 10~1000, roughness Ra 0.01~20 μm. Reports are issued to the standard edition on the drawing, and for export parts the grade system used must be stated explicitly.

3. Market and Exhibitions: A Dense Second-Half Schedule, Precision Part Enquiries Heating Up#

3.1 Exhibition Schedule#

The China International Industry Fair is held in Shanghai every September and is the window in which buyers of gears and transmission parts concentrate their enquiries; Hannover Messe is held in Germany every spring, and European buyers tend to place orders after the show. Several regional machinery and transmission exhibitions also fall in the second half of the year, and purchasing at gearbox makers and robotics companies is mostly released around those shows.

3.2 Changes on the Demand Side#

Along the lines of robot joint reducers, wind gearboxes and electric drive systems, the required gear accuracy grades are moving up: parts such as the circular spline/flexspline of harmonic reducers, planet gears and ring gears combine small batch size, high accuracy and short lead time, which suits factories with a complete grinding and inspection chain. The share of orders specifying DIN 4-6 grades is increasing, and at quotation the three parameters of module, pressure angle and helix angle are aligned first before grade and price are discussed.

4. Policy and Compliance: Export Acceptance Follows the Target Market Standard System#

4.1 Standard Systems Differ by Market, Report Basis Must Be Consistent#

North American orders are reported to AGMA, European orders to DIN or ISO, Japanese orders to JIS B 1702. The same batch of gears can correspond to several standard systems, but an inspection report can only state one basis, and the wrong system stalls acceptance. Confirming the customer’s acceptance standard at quotation stage is far easier than adding a report after delivery.

4.2 Material and Heat Treatment Standards Move Together#

Gear steel is selected to GB/T 3077; 20CrMnTi after carburizing and quenching has a core hardness of 30~42 HRC and a tensile strength of not less than 1080 MPa; 42CrMo after quenching and tempering is 269~321 HB. For export parts the material grade is cross-referenced to the target market (20CrMnTi ≈ AISI 4320, 42CrMo ≈ AISI 4140), and a material certificate is shipped with the goods, which reduces verification time at both customs and the customer end.

5. Related Geyontech Recommendations#

Serving gearbox and reducer manufacturers, robotics and automation, high-end equipment OEMs and precision transmission part traders, Geyontech offers:

• Precision ground gears: cylindrical gears module M1~M12, bevel gears M1~M10, grinding accuracy up to DIN 4-5 (Precision Gear Products)
• Standards and selection support: inspection reports to DIN/ISO/AGMA/GB, KISSsoft strength verification (Gear Product Center)
• Full-item inspection: gear measuring center plus meshing tester for pairing, report delivered with the goods

More technical material is available on the Geyontech website, or get in touch through the technical team.

Date: August 28, 2026 | Sources: ISO 1328, DIN 3961~3967, AGMA 2000/2015, GB/T 10095 standards, Geyontech product and inspection data