Cross-Referencing DIN and AGMA Gear Accuracy Classes: Tables, Selection Logic and Process Routing

1. Matching Grade to Process Route

• Target Grade DIN 4-5: Hobbing → Carburizing → Precision grinding
  • Key Equipment: Worm/form grinding machine
  • PinyiGear: as stated on the customer drawing
• Target Grade DIN 5~6: Hobbing → Carburizing → Grinding
  • Key Equipment: CNC grinder
  • PinyiGear: as stated on the customer drawing
• Target Grade DIN 6~7: Hobbing → Shaving or post-HT grinding
  • Key Equipment: Shaver/grinder
  • PinyiGear: Stable mass production
• Target Grade DIN 7~8: Precision hobbing
  • Key Equipment: High-precision hobbing machine
  • PinyiGear: Up to 5 sec/tooth
• Target Grade DIN 8~9: Standard hobbing
  • Key Equipment: Standard hobbing machine

2. How the Four Global Accuracy Systems Relate

Gear precision sits at the centre of transmission quality. It decides how quietly a drive runs, how much torque it can transmit, how smoothly the teeth engage, and how many service hours it delivers. Four systems set the rules in most markets.

• Standard DIN: German Industrial Standard
  • Region: Germany/Europe
  • Latest Version: DIN 3961~3967
  • Core Standard: DIN 3962 (Cyl. gear tolerances)
• Standard ISO: International Organization for Standardization
  • Region: Global
  • Latest Version: ISO 1328:2013
  • Core Standard: ISO 1328-1
• Standard AGMA: American Gear Manufacturers Association
  • Region: North America
  • Latest Version: AGMA 2015:2009
  • Core Standard: AGMA 2000-A88
• Standard GB: Chinese National Standard
  • Region: China
  • Latest Version: GB/T 10095:2008
  • Core Standard: GB/T 10095.1

GB/T 10095 is essentially ISO 1328 with national modifications, and DIN 3962 tracks ISO 1328 closely. In practice, DIN, ISO and GB share the same parameter definitions and can be used interchangeably. AGMA is the outlier: it applies a different grading logic entirely.

3. Grade Cross-Reference for Cylindrical Gears

• DIN Grade DIN 4-5: ISO 3
  • GB/T 10095: GB 3
  • AGMA 2000: AGMA 15
  • Typical Process: Precision grinding
  • Typical Application: Aerospace, high-speed, precision indexing
• DIN Grade DIN 4: ISO 4
  • GB/T 10095: GB 4
  • AGMA 2000: AGMA 14
  • Typical Process: Precision grinding
  • Typical Application: Auto transmission, precision machine tools
• DIN Grade DIN 5: ISO 5
  • GB/T 10095: GB 5
  • AGMA 2000: AGMA 13
  • Typical Process: Grinding/fine hobbing
  • Typical Application: Automotive, general gearboxes
• DIN Grade DIN 6: ISO 6
  • GB/T 10095: GB 6
  • AGMA 2000: AGMA 11~12
  • Typical Process: Hobbing + shaving
  • Typical Application: General industrial gearboxes
• DIN Grade DIN 7: ISO 7
  • GB/T 10095: GB 7
  • AGMA 2000: AGMA 10
  • Typical Process: Hobbing
  • Typical Application: Agricultural, crane machinery
• DIN Grade DIN 8: ISO 8
  • GB/T 10095: GB 8
  • AGMA 2000: AGMA 8~9
  • Typical Process: Hobbing
  • Typical Application: Low-speed, non-critical drives
• DIN Grade DIN 9~12: ISO 9~12
  • GB/T 10095: GB 9~12
  • AGMA 2000: AGMA 4~7
  • Typical Process: Rough cutting/casting
  • Typical Application: Manual, low precision

PinyiGear Batch Capability: Batch production and precision grinding are quoted against the tolerance class stated on the customer drawing.

4. What Each Precision Parameter Controls

4.1 Pitch Accuracy (Running Smoothness)

How evenly a drive passes motion along depends on pitch behaviour.

• Single Pitch Deviation (fpt/fp): variation between adjacent tooth pitches, which drives meshing impact noise.
• Total Cumulative Pitch Deviation (Fp): the maximum pitch error around the full circumference, which produces angular velocity fluctuation. This is the most critical parameter.
• Engineering rule: for general machinery, Fp ≤ 0.5×module (µm); precision drives require Fp ≤ 25 µm.

4.2 Tooth Profile Accuracy (Load Capacity)

• Total Profile Deviation (Fα): the gap between the actual profile and the theoretical involute, which sets how contact stress is distributed.
• Profile Form Deviation (ffα): curvature deviation, which excites micro-level noise.

4.3 Helix Accuracy (Axial Meshing)

Total Helix Deviation (Fβ) compares the actual tooth trace against the theoretical one and governs tooth load distribution. It is the primary cause of misalignment.

4.4 Radial Runout (Fr)

Eccentricity of the gear ring relative to the bore generates periodic noise and vibration.

5. Grade Versus Speed, Noise and Cost

6. Choosing a Grade for Your Export Market

6.1 Europe (DIN/ISO)

For everyday duties, DIN 5~7 is sufficient; where accuracy matters most, DIN 4-5 is the answer. A complete inspection report covering Fp/Fα/Fβ/Fr, together with a material certificate and a heat treatment report, is what European buyers normally ask for. Two items receive the closest scrutiny: surface roughness (Ra ≤ 0.8 µm) and tooth burn inspection.

6.2 North America (AGMA)

AGMA 11~13 covers general needs, while AGMA 14~15 serves precision work. Documentation usually includes a contact pattern check and a noise test. Note that imperial DP applies (DP = 25.4/m), so watch the DP/metric conversion.

6.3 Southeast Asia / Middle East

These markets generally reference DIN/ISO, though some follow JIS. DIN 6~8 is the usual recommendation, with cost-performance as the priority. Shipping protection matters here: anti-rust treatment plus soft tooth separators.

6.4 Precision Selection Decision Tree

Speed / Load / Noise requirements
 ├─ High speed >25m/s + Low noise → DIN 4-5 / AGMA 14~15 → Grinding
 ├─ Medium-high 15~25m/s → DIN 5~6 / AGMA 11~13 → Grinding/precision hobbing
 ├─ Medium 5~15m/s → DIN 6~7 / AGMA 10~11 → Hobbing+shaving
 └─ Low <5m/s → DIN 8~9 / AGMA 7~9 → Standard hobbing

7. Misconceptions Worth Correcting

• Higher precision is always better: Each grade adds 50~100% cost. Choose adequate, not highest
• DIN/ISO/GB are directly interchangeable: Parameters match, but DIN 4-5 tolerances are slightly stricter than ISO 3
• AGMA higher number = higher precision: Correct (AGMA 15 highest), but AGMA 15 ≠ DIN 7 — it equals DIN 4-5
• Hobbing can replace grinding for DIN 4: Hobbing limit ≈ DIN 4, but post-HT deformation requires grinding

8. PinyiGear Precision Capability

• Batch precision: GB 4~5 (consistent)
• Max grinding: DIN 4-5
• Full inspection: Gear measuring center + CMM + meshing tester
• Fp: ≤ 25 µm (DIN 5)
• Fα: ≤ 10 µm (DIN 4-5)
• Fβ: ≤ 10 µm (DIN 4-5)
• Fr: ≤ 15 µm
• Ra: ≤ 0.8 µm (grinding), ≤ 0.4 µm (superfinish)
• Report formats: DIN / ISO / AGMA / GB
• Certifications: CE / CSA / BV / SGS / UL

Accuracy class, module, tooth count and material follow the customer drawing.

9. Summary by Scenario

Send over the duty point of your application — power, speed, ratio and the country you ship to — and PinyiGear’s engineers will come back with a proposed accuracy class plus pricing as soon as the drawing review is finished.

Dongguan Pinyi Electromechanical Technology Co., Ltd. — maker of precision gears and exported transmission components

• sales@dgpinyi.com | dgpinyi.com*