Comparing Gear Accuracy Grades Across DIN, ISO, AGMA and GB Systems

Detailed explanation of the four major gear accuracy standard systems, with an accuracy grade comparison table to help customers select the appropriat

How the Four Accuracy Systems Line Up

Different regions classify gear accuracy in their own ways, and the four systems below are the ones most often encountered in drawings and purchase specifications. The table maps equivalent grades against one another, together with the production route normally used to reach each level and the kinds of applications it serves.

  • Machining Method Gear grinding: Aerospace gears, precision instruments
    • DIN (Germany): DIN 4-5
    • ISO (International): ISO 3
    • AGMA (USA): AGMA 14~15
    • GB (China): GB Grade 3
  • Machining Method Gear grinding: High-speed transmissions, precision machine tools
    • DIN (Germany): DIN 4
    • ISO (International): ISO 4
    • AGMA (USA): AGMA 12~13
    • GB (China): GB Grade 4
  • Machining Method Gear grinding/gear shaving: Automotive transmissions, precision machinery
    • DIN (Germany): DIN 5
    • ISO (International): ISO 5
    • AGMA (USA): AGMA 10~11
    • GB (China): GB Grade 5
  • Machining Method Gear shaving/gear grinding: General machinery, industrial equipment
    • DIN (Germany): DIN 6
    • ISO (International): ISO 6
    • AGMA (USA): AGMA 8~9
    • GB (China): GB Grade 6
  • Machining Method Gear hobbing/gear shaping: Ordinary machinery, conveying equipment
    • DIN (Germany): DIN 7
    • ISO (International): ISO 7
    • AGMA (USA): AGMA 7~8
    • GB (China): GB Grade 7

What PinyiGear Holds in Routine Production

Module, diameter, tooth count and accuracy grade follow the customer drawing.

Related reading