Gear module in mm (metric sizing). Module = pitch diameter / number of teeth. Standard modules per ISO 54: 1, 1.25, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10. Provide either module_mm or diametral_pitch, not both.

Diametral pitch in teeth per inch (imperial sizing). Pd = N/d. Common values: 3-20 for power gears, 20-200 for instrument gears. Provide either diametral_pitch or module_mm, not both.

Number of teeth on the pinion (smaller driving gear). Minimum 12-13 teeth to avoid undercutting with 20-degree pressure angle. Fewer teeth increase bending stress.

Number of teeth on the driven gear. Gear ratio = num_teeth_gear / num_teeth_pinion. Higher tooth counts reduce noise and improve contact ratio. Typical: 20-100. Gear ratio = N_gear / N_pinion.

Pressure angle in degrees. Standard values: 14.5, 20, or 25 degrees. 20 degrees is the most common modern standard per AGMA. Higher angles increase load capacity but also bearing loads. Standard values: 14.5° (obsolete), 20° (most common), 25° (heavy loads). If omitted, defaults to 20.0 degrees.

Gear face width in mm. AGMA recommends 8-16 times the module. Too narrow increases stress; too wide causes uneven load distribution.

Rotational speed of the pinion in revolutions per minute. Determines pitch line velocity, which affects the AGMA dynamic factor Kv. Typical: 600-3600 rpm for motor-driven gearboxes.

Power transmitted through the gear pair in kilowatts. Used to calculate the tangential tooth load Wt for bending and contact stress analysis. Typical: 0.5-100 kW for industrial gearboxes.

AGMA quality number per AGMA 2000-A88. Range 3-12, higher is better. Typical: 6-8 for commercial gears, 10-12 for precision/aerospace. Affects the dynamic factor Kv. If omitted, defaults to 8.